0:00:02 > 0:00:05Seven young explorers have taken on their biggest challenge,
0:00:05 > 0:00:07an epic adventure in the heart of Africa.
0:00:07 > 0:00:11It'll take them far from civilisation,
0:00:11 > 0:00:14- encountering endangered wildlife... - Such an adrenaline rush!
0:00:14 > 0:00:17..witnessing unique tribal ceremony...
0:00:17 > 0:00:21- Ah, wow!- ..and trekking where none have been before.
0:00:21 > 0:00:22It's so amazing!
0:00:22 > 0:00:24They're following in the footsteps
0:00:24 > 0:00:28of the great Scottish explorer, Dr David Livingstone.
0:00:28 > 0:00:32And the demanding expedition will push them to the very limit.
0:00:32 > 0:00:33It is a wake-up call.
0:00:33 > 0:00:36- It's horrible!- I hate it.
0:00:36 > 0:00:40Have they got what it takes to be serious explorers?
0:00:44 > 0:00:46Coming up...
0:00:46 > 0:00:48battling the blisters...
0:00:48 > 0:00:50It is ridiculous, I give you that.
0:00:50 > 0:00:52..a rare day of pampering...
0:00:52 > 0:00:54Can't get it off.
0:00:54 > 0:00:57..and who will be chosen as the top three explorers?
0:00:57 > 0:01:00Any single one of you could have gone forward.
0:01:01 > 0:01:05Previously, the seven explorers set out on a superhuman trek,
0:01:05 > 0:01:08an 11-day hike of more than 100 miles
0:01:08 > 0:01:12across Tanzania's remote Mbarika Mountains.
0:01:12 > 0:01:15No expedition has ever crossed the mountains before,
0:01:15 > 0:01:19and it's so tough that all but the strongest turn back after two days.
0:01:19 > 0:01:24We're going to be taking three people forward. Only three.
0:01:25 > 0:01:28Sian struggled to cope with trekking up to ten miles a day...
0:01:28 > 0:01:30I hate not being able to do it.
0:01:30 > 0:01:34..and an old knee problem gave Ashleigh serious grief.
0:01:34 > 0:01:37Part of me wants to give up but I know that if I do, I'll regret it.
0:01:37 > 0:01:39Yay! It's so exciting!
0:01:39 > 0:01:44But surprise packages from home helped raise team morale.
0:01:44 > 0:01:46I'm happy that everyone back home's rooting for me.
0:01:46 > 0:01:49It has definitely given me the strength I need.
0:01:51 > 0:01:55It's 5am on Mbarika trek day two,
0:01:55 > 0:01:59and assistant leader Polly has to wake the team.
0:01:59 > 0:02:01It's time to get up. Are you feeling a bit tired?
0:02:01 > 0:02:06GRUNTS
0:02:06 > 0:02:08- How are we doing?- Good.- Tired.
0:02:08 > 0:02:13- Are you ready for another day? - No! I'm never ready for another day!
0:02:13 > 0:02:17Yesterday's long, hot trek has left them exhausted,
0:02:17 > 0:02:21but expedition leader Ben is not impressed with the lack of action.
0:02:21 > 0:02:24You've had 40 minutes and you haven't even got a tent down yet.
0:02:24 > 0:02:26An hour is plenty of time to get packed up.
0:02:26 > 0:02:28Who's in there?
0:02:28 > 0:02:32It's not good enough. Should be five minutes, outside, tents down.
0:02:32 > 0:02:37As usual, James is the only one who's managed to get organised.
0:02:37 > 0:02:39James is too good in the morning!
0:02:39 > 0:02:43I know! By the time I sit up, he's out of his tent
0:02:43 > 0:02:46- and putting the tent down. - Yeah, I know!
0:02:46 > 0:02:50Today is the explorers' last chance to show they've the right stuff
0:02:50 > 0:02:54to tackle the entire record-breaking trek.
0:02:56 > 0:02:59David Livingstone himself had amazing determination,
0:02:59 > 0:03:02trekking for years on end into unexplored territory.
0:03:02 > 0:03:06His diary shows he found it very rewarding.
0:03:06 > 0:03:10"The effect of travel on a man whose heart is in the right place
0:03:10 > 0:03:13"is that the mind is made more self-reliant and confident."
0:03:14 > 0:03:18His last expedition lasted five years and saw him
0:03:18 > 0:03:22cross Tanzania all the way to Lake Tanganyika.
0:03:22 > 0:03:25The three young explorers who trek right across the Mbarikas
0:03:25 > 0:03:29will also be going where no expedition has been before.
0:03:31 > 0:03:34But who will be in the elite team of three?
0:03:34 > 0:03:36With the big decision looming,
0:03:36 > 0:03:40today's nine-mile trek is a last chance to impress the leaders.
0:03:40 > 0:03:42- Fresh pooh!- Yep.
0:03:46 > 0:03:50Conditions are much cooler than yesterday, with thick cloud cover.
0:03:52 > 0:03:56THEY SING A MARCHING SONG
0:03:56 > 0:04:02As they approach their first break, the team's spirits are much higher.
0:04:02 > 0:04:05It's the first walk I've enjoyed because of the temperature.
0:04:05 > 0:04:07We had the choir as well.
0:04:07 > 0:04:11- We are so good.- We must have gone through so many songs!
0:04:12 > 0:04:17But it's about to get tougher, as the route gets steeper and steeper.
0:04:17 > 0:04:20We've only been walking downhill so hopefully it's uphill
0:04:20 > 0:04:26we'll feel the same but hopefully it may be a little, tiny bit harder!
0:04:30 > 0:04:33The leaders are watching their every move to see who's got the mental
0:04:33 > 0:04:36and physical strength to spend nine more days in the mountains.
0:04:36 > 0:04:38Uh-oh.
0:04:39 > 0:04:43I've just seen where we'll first be climbing up to.
0:04:43 > 0:04:46It's like a cliff edge! I don't know how we're going to get up there.
0:04:51 > 0:04:54I have a bit of a blister on my little toe
0:04:54 > 0:04:58that I'm about to tape up to stop it getting worse.
0:04:59 > 0:05:01After four hours of trekking,
0:05:01 > 0:05:05the team need to dig deep for the final steep push to camp.
0:05:09 > 0:05:11Look down there, to the left.
0:05:11 > 0:05:17Incredible view. I think we'll get such a sense of achievement.
0:05:18 > 0:05:22Several of the team struggled yesterday, especially Sian...
0:05:24 > 0:05:27..but today they all finish strongly to reach their camp site.
0:05:27 > 0:05:29Woo!
0:05:29 > 0:05:31- Did you enjoy that? - Yeah, that was brilliant.
0:05:31 > 0:05:35That was brilliant, team. Really, really cool.
0:05:35 > 0:05:38Sian is overwhelmed by her achievement.
0:05:38 > 0:05:40I'm so happy I did that.
0:05:42 > 0:05:46I think even the fittest would struggle with that.
0:05:46 > 0:05:48I'm so proud of myself and everyone here.
0:05:48 > 0:05:53I thought I'd struggle more than that. I'm sweaty and my shirt stinks.
0:05:53 > 0:05:58They loved it. I really didn't think they'd all make it up so fast
0:05:58 > 0:06:00and in such high spirits.
0:06:01 > 0:06:04It leaves Ben and Polly with a difficult decision.
0:06:04 > 0:06:07Which three earned the Serious Explorers badge of honour,
0:06:07 > 0:06:11capable of achieving a world first by crossing the Mbarikas?
0:06:13 > 0:06:18What's amazing is today, every single one of them stepped up to the mark.
0:06:18 > 0:06:22And worked really, really hard and they could all do it.
0:06:24 > 0:06:27I would love to do the mountain-walking.
0:06:27 > 0:06:31I think it would create a bigger high at the end of the experience.
0:06:31 > 0:06:34I'm quite nervous because I really want to get into the nine-day walk.
0:06:36 > 0:06:39Even Sian who wasn't that happy yesterday...
0:06:39 > 0:06:43- you know, at the top of that hill, she was beaming smile.- I know.
0:06:43 > 0:06:45And really proud of what she'd done.
0:06:45 > 0:06:48I think there's people here who are stronger than me
0:06:48 > 0:06:50but if they chose me, I'd give it my best shot.
0:06:52 > 0:06:55I'd like to get chosen but if I didn't, I wouldn't be too upset
0:06:55 > 0:06:57cos I know it's just going to be so hard.
0:07:01 > 0:07:04I'll be happy for anyone that gets in.
0:07:04 > 0:07:07I think we all deserve it but I'd love to do it.
0:07:09 > 0:07:11They're a strong, strong team.
0:07:11 > 0:07:15The young explorers gather together to hear their fate.
0:07:15 > 0:07:18Any single one of you could have gone forward. All right?
0:07:18 > 0:07:24Polls is starting us off and we will tell you who is going where and why.
0:07:24 > 0:07:27Those chosen by Polly will head back with her
0:07:27 > 0:07:30to work on a tribal building project.
0:07:30 > 0:07:32The first person I'm going to choose is Ashleigh.
0:07:32 > 0:07:36You're fit as a fiddle but we don't want to damage your knees.
0:07:36 > 0:07:41Next, Ben reveals the first explorer who's made it on to his team.
0:07:41 > 0:07:43Coming with me is James.
0:07:43 > 0:07:48I think you have worked incredibly hard over the last few days.
0:07:48 > 0:07:51And I think you are going to be an asset to the team.
0:07:51 > 0:07:55I am going to take David as well. Um...
0:07:55 > 0:07:58Don't look so excited(!)
0:07:58 > 0:08:01So who's next for the elite trekking team?
0:08:01 > 0:08:04Cassie, you're going to come with me.
0:08:04 > 0:08:07No complaints, just get on with it.
0:08:07 > 0:08:10And I'll follow up with Sian. I think you could do it.
0:08:10 > 0:08:11You shone through today.
0:08:11 > 0:08:17But your mental attitude is still a little bit up and down.
0:08:19 > 0:08:24Which leaves the final place in Ben's top team between Ali and Matt.
0:08:24 > 0:08:28Who is it going to be? Eeny, Meeny, Miney, Moe.
0:08:28 > 0:08:29Matt.
0:08:29 > 0:08:31Oh! No, only joking.
0:08:31 > 0:08:33You're coming with me, mate. Physically, strong guy.
0:08:33 > 0:08:37- We can load you up like a donkey with loads of kit.- Yeah, cheers(!)
0:08:37 > 0:08:39The guys who are going forward, congratulations,
0:08:39 > 0:08:43cos you are going to have the most incredible journey,
0:08:43 > 0:08:47but the guys who are with me, we're going to be working very hard.
0:08:47 > 0:08:51Polly's team will be flying to the north of Tanzania
0:08:51 > 0:08:53to live with the Masai tribe,
0:08:53 > 0:08:56building a lion-proof enclosure to protect their animals.
0:08:56 > 0:08:59And there's an extra surprise.
0:08:59 > 0:09:03We're also going to be doing a darting project with lion.
0:09:03 > 0:09:06OK? And tagging it with a GPS.
0:09:06 > 0:09:10- We get to see a lion! - We get to trek all day and night!
0:09:10 > 0:09:12Lucky Cassie(!)
0:09:12 > 0:09:15Most are really pleased with the leaders' decisions.
0:09:15 > 0:09:20When Ben was going to pick, I was like, James, James!
0:09:20 > 0:09:22I really wanted to get in. I'm so happy.
0:09:22 > 0:09:25Last night, I wanted to go and then this morning, I didn't.
0:09:25 > 0:09:30And then in the middle I kind of did and then I didn't want to any more.
0:09:30 > 0:09:32So I'm quite happy.
0:09:32 > 0:09:38But Ashleigh's disappointed she's lost the chance to test her limits.
0:09:38 > 0:09:41I am pretty gutted. I really wanted to do the walk.
0:09:41 > 0:09:45Because there's so much I need to learn about myself.
0:09:45 > 0:09:51Though Matt has made it onto the team, he seemed less than ecstatic.
0:09:51 > 0:09:55It makes me feel happy they think I'm the right man for the job but...
0:09:55 > 0:09:57well, we'll see!
0:09:57 > 0:10:01That's for the team going forward, obviously to plot the route,
0:10:01 > 0:10:04- can someone pop it in a bag and look after it?- I'll lose it.
0:10:04 > 0:10:06You won't lose it, mate.
0:10:06 > 0:10:08- Matt, it's yours.- It's yours.
0:10:08 > 0:10:11You're the man for the job!
0:10:11 > 0:10:15As Matt's mood worsens, he refuses to talk to anyone.
0:10:15 > 0:10:19So, David and Ali decide to try and guess how he's feeling.
0:10:19 > 0:10:21Depressed... Unhappy...
0:10:21 > 0:10:24Sad...
0:10:24 > 0:10:29- Scared?- I think Matt was looking forward to the trek
0:10:29 > 0:10:32until he figured out how much pain he's going to be going through.
0:10:32 > 0:10:35I think Ali summed it up the best, really. Yeah.
0:10:38 > 0:10:42It's the team's last night together before they spend nine days apart.
0:10:42 > 0:10:45It's going to be so weird not being in a big group,
0:10:45 > 0:10:47just being in a three, and I'm going to be the only girl.
0:10:47 > 0:10:50So I'm going to embrace all my girlie-ness now!
0:10:50 > 0:10:54I'm going to miss you, Cassie.
0:10:54 > 0:10:57- You'll see me soon. - Who's going to sew my trousers?
0:10:57 > 0:11:00Worryingly, James has found a sore patch on his feet.
0:11:00 > 0:11:04He decides to treat it himself, confident he has it sorted.
0:11:04 > 0:11:07I taped them up and everything is ready to go for a hard walk tomorrow.
0:11:07 > 0:11:10It's going to be tough but I think my body can take it.
0:11:10 > 0:11:13- Good night, everyone. - Good night, everyone.
0:11:13 > 0:11:15Thanks for a great time so far, cos we won't be with you.
0:11:15 > 0:11:18- Guys, I hate all of you. - Love you too, man!
0:11:18 > 0:11:20Nice not spending nine days with you!
0:11:20 > 0:11:23- Nine days in hell!- It's going to be hardcore, though, isn't it?
0:11:29 > 0:11:32No choice. Up! Up!
0:11:32 > 0:11:345am on the day of the split.
0:11:34 > 0:11:38Last morning together for a little while.
0:11:40 > 0:11:45As usual, James leads the way, raring to get going.
0:11:45 > 0:11:46James is on the move.
0:11:46 > 0:11:49Six minutes and he'll be dropping the tent.
0:11:49 > 0:11:51I'm getting kicked out!
0:11:51 > 0:11:54Get out of Hurricane James's way!
0:11:54 > 0:11:59They say he can take down a tent in 0.3 seconds.
0:11:59 > 0:12:02THEY LAUGH
0:12:02 > 0:12:05I got up early, I still have packing. But he still won!
0:12:05 > 0:12:08Last to get up, first to get out.
0:12:10 > 0:12:14The moment has arrived. The porters are ready for us to set off.
0:12:14 > 0:12:17- I don't want to go. - I've got to hug you.
0:12:17 > 0:12:21- Bye.- Bye bye. - Enjoy the lions.- Take care.
0:12:21 > 0:12:24- Enjoy the lions, yeah? - Good luck, guys.- Good luck!
0:12:24 > 0:12:26See you, guys.
0:12:26 > 0:12:27Good luck!
0:12:29 > 0:12:32Ben's team face a further nine-day trek over 100 miles
0:12:32 > 0:12:35across the Mbarika Mountains,
0:12:35 > 0:12:37while Polly's group have a two-day journey
0:12:37 > 0:12:41retracing their steps back to the Selous before flying north
0:12:41 > 0:12:45to the Tarangire National Park, to work on their lion projects.
0:12:53 > 0:12:57Ben's marathon trekking team is almost 40 strong,
0:12:57 > 0:13:00including several armed guards and 20 porters.
0:13:01 > 0:13:06Even so, Matt, Cassy and James have to carry their heaviest loads yet.
0:13:06 > 0:13:10Even this hill, with this weight, the weight really makes a difference.
0:13:10 > 0:13:12It makes it a lot harder.
0:13:12 > 0:13:15It's OK at the moment. The uphill gets a bit strenuous on your legs.
0:13:18 > 0:13:22Meanwhile, Polly's team are heading in the opposite direction.
0:13:22 > 0:13:24It is kind of depressing to be walking back
0:13:24 > 0:13:26in the same way that we came
0:13:26 > 0:13:28but I still get to do something that's really fun.
0:13:28 > 0:13:34I'm sure the other guys will enjoy the walking 100 miles a lot...
0:13:34 > 0:13:39but I'm going to so much more enjoy what I'm about to do.
0:13:39 > 0:13:42Deep in the mountains, Matt's still finding the scale
0:13:42 > 0:13:44of what he's taken on pretty daunting.
0:13:46 > 0:13:51I've just seen what's in front of us and there's a million hills,
0:13:51 > 0:13:53all steeper than the one we just climbed.
0:13:55 > 0:13:58By early afternoon, they complete their day's ten miles
0:13:58 > 0:14:02and James winds down with some stretching exercises.
0:14:03 > 0:14:05I'm finding it fine today.
0:14:05 > 0:14:09It's pretty good at the moment. I'm excited about making camp tonight.
0:14:11 > 0:14:14But his team-mates, Cassie and Matt, are in low spirits.
0:14:14 > 0:14:18I'm just thinking about people at home and things now.
0:14:20 > 0:14:22But, I'm like, happy at the same time,
0:14:22 > 0:14:26because today, it's the halfway point and it's like...
0:14:27 > 0:14:31..it's two and a bit weeks until I see everyone again.
0:14:31 > 0:14:32Which is good.
0:14:32 > 0:14:34Every day is, like, exactly the same.
0:14:34 > 0:14:40It's just get up, walk, get to camp, sleep, get up again.
0:14:40 > 0:14:42It's like nothing changes.
0:14:42 > 0:14:46And just as they're are about to make camp, Ben has some bad news.
0:14:46 > 0:14:49I know people are suffering all the streams are dried up,
0:14:49 > 0:14:51we've got to hunt for water.
0:14:51 > 0:14:56I'm sorry, but we're pushing on and pushing on until we find water.
0:14:57 > 0:15:02On long expeditions, it's impossible to carry all the water you need,
0:15:02 > 0:15:06so Livingstone and his men spent much of their time searching for it.
0:15:06 > 0:15:10"No-one knows the value of water until he is deprived of it.
0:15:10 > 0:15:14"I have drunk water swarming with insects, thick with mud,
0:15:14 > 0:15:18"and putrid with rhinoceros urine and buffalo's dung."
0:15:18 > 0:15:20Without modern ways of purifying it,
0:15:20 > 0:15:24the filthy water gave him many diseases.
0:15:24 > 0:15:26We've got to conserve what little what we've got left
0:15:26 > 0:15:29and share it out amongst us.
0:15:29 > 0:15:30Have you got any water left?
0:15:30 > 0:15:32None at all. Have you, James?
0:15:32 > 0:15:35- A litre-plus.- A litre-plus?
0:15:35 > 0:15:40Could you give a third of a litre, or whatever, to Matt? Yeah?
0:15:40 > 0:15:42Cos Matt's the guzzler.
0:15:42 > 0:15:45I'm just thankful that James has actually given me some because...
0:15:45 > 0:15:50you know, we've all had the same. I've just...drunk it all.
0:15:50 > 0:15:52- Cheers.- Don't drink it now.
0:15:56 > 0:16:00Meanwhile, Polly's group complete their day's nine-mile journey,
0:16:00 > 0:16:02arriving back at a familiar campsite.
0:16:02 > 0:16:07Everything's set up, so literally we have to get a new fire on the go,
0:16:07 > 0:16:09tents back up, that's pretty much it.
0:16:09 > 0:16:11It brings back memories from when we got our passes
0:16:11 > 0:16:14and we had such a good night that night.
0:16:14 > 0:16:15THEY CHATTER AND LAUGH
0:16:15 > 0:16:18It's just exciting to be back.
0:16:18 > 0:16:21Unfortunately, some unpleasant neighbours have moved in.
0:16:21 > 0:16:25So, just like Ben, Polly has some bad news for her team.
0:16:25 > 0:16:27There's millions and millions of ants.
0:16:27 > 0:16:31We can't stay up here, cos we'll get eaten alive.
0:16:31 > 0:16:34The only safe option is to continue all the way back
0:16:34 > 0:16:38out of the mountains to their original base camp in the Selous.
0:16:38 > 0:16:40We'll head down to the fig tree camp.
0:16:40 > 0:16:45It does mean that tomorrow, we might have a little bit of a free day.
0:16:45 > 0:16:47Yay!
0:16:47 > 0:16:50It is another 6.5 miles. It's quite a big ask,
0:16:50 > 0:16:55they're not enthusiastic but we need to go. It'll be dark in three hours.
0:16:55 > 0:16:58My feet are aching, but I just say get on and do it.
0:16:59 > 0:17:02Ben's team have got a second wind,
0:17:02 > 0:17:06piling on more punishing miles in a desperate search for water.
0:17:08 > 0:17:13And Polly's group are also rising to the challenge of their extra trek.
0:17:14 > 0:17:16Urgh!
0:17:18 > 0:17:20After hiking a total of 12 miles,
0:17:20 > 0:17:24there's a welcome sight at last for Ben's parched team!
0:17:26 > 0:17:29End of a long day's trek.
0:17:29 > 0:17:33We all wanted to see some water, we all really needed it.
0:17:33 > 0:17:38I don't know if it's running or not, but...it's still good.
0:17:38 > 0:17:40Polly's team have trekked even further than Ben's group
0:17:40 > 0:17:44by the time their original base camp is in sight.
0:17:45 > 0:17:48I feel so relieved that we're, like literally there,
0:17:48 > 0:17:50and I can't wait to eat.
0:17:50 > 0:17:54I can't believe we've walked 15 miles today. It's been incredible.
0:17:54 > 0:17:59Good effort. That was not easy. Well done.
0:18:01 > 0:18:05The stream found in the Mbarikas is stagnant and dirty,
0:18:05 > 0:18:10so the explorers dig down to find cleaner water, filtered by the sand.
0:18:10 > 0:18:13Unlike Livingstone, they use chemicals to purify it
0:18:13 > 0:18:15and make it safe to drink.
0:18:18 > 0:18:22It's really interesting to see how we take water for granted,
0:18:22 > 0:18:23it just shows you how much,
0:18:23 > 0:18:26when we glug down water at home,
0:18:26 > 0:18:29how much these people really do need it.
0:18:29 > 0:18:31It's been a hugely demanding day
0:18:31 > 0:18:34but Ben has news of even tougher times ahead.
0:18:34 > 0:18:38Their route will soon take them over a 4,000-ft peak.
0:18:38 > 0:18:41This is the highest point along our route.
0:18:41 > 0:18:44And we want to go up it.
0:18:44 > 0:18:46So, it's just over 1,000 metres.
0:18:46 > 0:18:48And hopefully, if we get our timing right,
0:18:48 > 0:18:51we might see the other group fly over the top of us.
0:18:51 > 0:18:53Oh, that would be so good!
0:18:55 > 0:18:58As David Livingstone trekked into the unknown,
0:18:58 > 0:19:01he was the first explorer to tackle many mountains.
0:19:01 > 0:19:04It enabled him to check out the way forward
0:19:04 > 0:19:06and also the breathtaking scenery.
0:19:06 > 0:19:11"We looked with never-failing delight on fertile plains, numerous hills,
0:19:11 > 0:19:13"and majestic mountains."
0:19:15 > 0:19:18And in the true spirit of Livingstone,
0:19:18 > 0:19:22the peak faced by the explorers has never been conquered before.
0:19:22 > 0:19:27Now that we're climbing a massive mountain, that scaring me a bit.
0:19:27 > 0:19:30It's bad enough just going up and down and up and down.
0:19:30 > 0:19:32I think it's really hit home for the others.
0:19:32 > 0:19:35It's not going to be a walk in the park. This is tough.
0:19:35 > 0:19:39Matt is still struggling to see the point of the endless trekking.
0:19:39 > 0:19:40It was hard.
0:19:40 > 0:19:43Hills just up, down, up, down, up, up, up, up, up,
0:19:43 > 0:19:45down, up, down, up, down.
0:19:45 > 0:19:47Up. Down.
0:19:47 > 0:19:49Just the whole way.
0:19:49 > 0:19:51With Matt, he finds it boring, you know?
0:19:51 > 0:19:54At the moment, is he enjoying it? I don't think he'd admit it
0:19:54 > 0:19:57but I think he will come round and suddenly go,
0:19:57 > 0:19:59"Actually, yeah. This is special."
0:19:59 > 0:20:03James has always been supremely confident in the wild
0:20:03 > 0:20:06but next morning he wakes up with a problem all of his own making.
0:20:07 > 0:20:10Oh, that's a goodie. We'll have to drain that.
0:20:10 > 0:20:13So the Hurricane might be walking slightly slower today.
0:20:13 > 0:20:15Medic Fiona treats the huge blister.
0:20:15 > 0:20:17A tiny little hole there
0:20:17 > 0:20:19and the fluid's going to drain out of its own accord.
0:20:19 > 0:20:22Urgh! I can feel it dripping down my leg!
0:20:22 > 0:20:25So Hurricane's out the window today. It's now James Tenderfoot.
0:20:25 > 0:20:27Hopefully it won't be too sore.
0:20:27 > 0:20:29I did put something on it before
0:20:29 > 0:20:31but not in the right area, I put it too high up.
0:20:31 > 0:20:37So, yeah, it just shows, get the tape on before anything happens.
0:20:38 > 0:20:42You can just feel the heat of the sun coming up, can't you?
0:20:42 > 0:20:44With the temperature already rising,
0:20:44 > 0:20:48they set off on their day's 11-mile hike.
0:20:49 > 0:20:54While Polly's group are having a lie in for the first time in two weeks.
0:20:54 > 0:20:56Ali?
0:20:56 > 0:20:58Can you wake up now?
0:20:58 > 0:20:59My God!
0:20:59 > 0:21:02I woke up and it was still dark, I was like,
0:21:02 > 0:21:05"Oh no, Ben's going to be telling me to get up in a second."
0:21:05 > 0:21:08Then I realised, "Oh, no, wait a second, I can relax today!
0:21:08 > 0:21:11Unlike the Mbarika team.
0:21:11 > 0:21:15As the trekking continues, James is having problems with his blisters.
0:21:15 > 0:21:19That's the area of pressure.
0:21:19 > 0:21:22Out with the tape. Look at the state of this.
0:21:22 > 0:21:24It is ridiculous, I give you that.
0:21:24 > 0:21:28- Where is it sore? Here?- On the edge, then along the top there.
0:21:28 > 0:21:32We all knew he wasn't really strong, he was just putting it on.
0:21:32 > 0:21:33Old Tenderfoot James?
0:21:33 > 0:21:37He tries to power on but all you hear is whinge, whinge, whinge.
0:21:37 > 0:21:41He used to be the strongest in the group but now...
0:21:41 > 0:21:43Humiliation is complete.
0:21:45 > 0:21:50With the tropical sun burning down, the others cool down in the river,
0:21:50 > 0:21:53getting their first proper wash in a week.
0:21:53 > 0:21:56I do feel for the other guys because they are walking through this
0:21:56 > 0:21:58but, yeah, we're having a brilliant day.
0:22:03 > 0:22:07The Mbarika party are sweating it out in incredibly tough terrain.
0:22:13 > 0:22:15We're just chopping things out the way.
0:22:15 > 0:22:20It's amazing to be thinking no-one's actually ever been here.
0:22:20 > 0:22:22Back at base camp,
0:22:22 > 0:22:25it's an expedition first of a different kind.
0:22:25 > 0:22:26It feels horrible!
0:22:26 > 0:22:28They're cleansing their skin
0:22:28 > 0:22:31using face packs sent in Sian's parcel from home.
0:22:32 > 0:22:34Quite sticky on your eyelashes.
0:22:34 > 0:22:37Don't get it on your eyebrows, eyelashes, in your eyes
0:22:37 > 0:22:38Now you say that!
0:22:38 > 0:22:42THEY ALL LAUGH
0:22:42 > 0:22:44These guys are wimps, they don't like it.
0:22:44 > 0:22:46I wonder if Livingstone did this.
0:22:46 > 0:22:50- Can't get it off!- You look like something out of a horror movie.
0:22:50 > 0:22:53This is the last time you are going to see us peeling my face off.
0:22:54 > 0:22:57The trekkers are having a more serious time,
0:22:57 > 0:23:00battling up more steep slopes.
0:23:01 > 0:23:04And just as they clock up their day's 11 miles,
0:23:04 > 0:23:08they get their first glimpse of the peak they'll be tackling tomorrow.
0:23:08 > 0:23:10It's huge!
0:23:10 > 0:23:13Imagine what the view will be like when we get to the top.
0:23:13 > 0:23:15It's going to be hard.
0:23:15 > 0:23:17Despite the challenge to come,
0:23:17 > 0:23:19the day has left Matt feeling more positive.
0:23:19 > 0:23:24I think I've kind of changed my outlook on things a little.
0:23:24 > 0:23:27I'm trying not to look forward to the end because I want to enjoy this.
0:23:27 > 0:23:29Matt suddenly realised,
0:23:29 > 0:23:31"Hang on a minute, we are off the beaten track here,
0:23:31 > 0:23:34"we are exploring and actually it's quite exciting."
0:23:34 > 0:23:36It's nice to see that change.
0:23:38 > 0:23:41James has shown his usual strength of mind to battle on
0:23:41 > 0:23:44with his terrible blisters. But it's been a painful lesson.
0:23:44 > 0:23:47Small problems can become big problems very quickly.
0:23:47 > 0:23:51The big blister that caused dramas to start with was caused yesterday
0:23:51 > 0:23:54and he didn't actually... put his hand up
0:23:54 > 0:23:57and say, "You know what, I've got a problem, can we stop?"
0:23:57 > 0:24:01I'm worried about the steep stuff because if it gets bad at that stage,
0:24:01 > 0:24:04I won't be able to walk on. Then that's the trip ruined, really.
0:24:09 > 0:24:13It's the morning of the big climb, and the explorers are nervous.
0:24:13 > 0:24:16I want to go back to sleep
0:24:16 > 0:24:21and not have to climb up a big, fat mountain thing.
0:24:21 > 0:24:23I'm trying to keep a positive mental, kind of like, mind
0:24:23 > 0:24:26but I don't know how long that's going to last.
0:24:26 > 0:24:31I'm looking forward to it just to get to the top and see the view.
0:24:31 > 0:24:33It's going to be such a good feeling.
0:24:33 > 0:24:35Let's do it, gang.
0:24:37 > 0:24:41They face a 4,000-foot ascent, up seriously steep slopes,
0:24:41 > 0:24:44with the temperature already 30 degrees and rising.
0:24:49 > 0:24:53Suddenly, an unexpected hazard brings the expedition to a halt.
0:24:55 > 0:24:59THE PORTERS CHATTER
0:24:59 > 0:25:02A dangerous snake has been disturbed at the front of the line.
0:25:03 > 0:25:07Someone stumbled across a huge snake. We're trying to establish where it is
0:25:07 > 0:25:09and try and get a safe route through.
0:25:09 > 0:25:11It's on the tree, yeah?
0:25:12 > 0:25:13Black mamba.
0:25:13 > 0:25:16They're like really poisonous.
0:25:17 > 0:25:20He just needed to smell the air and get out of our way, really.
0:25:20 > 0:25:23We're going to move through, underneath, out of its way.
0:25:23 > 0:25:26It's one of the deadliest snakes in Africa
0:25:26 > 0:25:28so it's not the snake you mess around with.
0:25:28 > 0:25:31I'm really scared about where I'm stepping
0:25:31 > 0:25:34in case I step on one and get bitten.
0:25:41 > 0:25:44The higher they climb, the steeper the route
0:25:44 > 0:25:46and the more stunning the scenery.
0:25:46 > 0:25:50- Whoa!- What a view!
0:25:50 > 0:25:52See how steep it is off the side.
0:25:52 > 0:25:54- Big drop off.- Woo!
0:25:56 > 0:25:58Polly's team are about to fly to the north of Tanzania.
0:25:58 > 0:26:01But they'll divert over the Mbarikas,
0:26:01 > 0:26:03in the hope of catching sight of the climbers.
0:26:06 > 0:26:09So exciting! I can't wait to see all the rest of the group.
0:26:09 > 0:26:11It would be so cool to see them.
0:26:11 > 0:26:13Meanwhile, the three young climbers
0:26:13 > 0:26:16are starting their final push up the mountain.
0:26:29 > 0:26:33And after three gruelling hours, Matt, James and Cassie
0:26:33 > 0:26:38become the first explorers ever to reach the summit.
0:26:38 > 0:26:40Woo!
0:26:40 > 0:26:43THEY SING
0:26:43 > 0:26:45Woo!
0:26:49 > 0:26:54There aren't many unclimbed peaks in the world. You guys just done one.
0:26:54 > 0:26:57No-one else has ever been here before, so that's so amazing.
0:26:57 > 0:27:00I can't find any words to describe how good it feels
0:27:00 > 0:27:03just to be the first people up here.
0:27:05 > 0:27:07- Can you see them?- Look.
0:27:07 > 0:27:09There they are! There they are!
0:27:09 > 0:27:12Oh, there they are. There they are!
0:27:12 > 0:27:14Woo! Yay!
0:27:14 > 0:27:17- Woo!- Woo!
0:27:17 > 0:27:20- That was brilliant!- So good!
0:27:20 > 0:27:22It's amazing seeing them all, I'm so proud of them!
0:27:24 > 0:27:27Such an achievement, all the hard times
0:27:27 > 0:27:29over the last couple of days has been forgotten.
0:27:29 > 0:27:33They genuinely are explorers because this has never been done before.
0:27:33 > 0:27:37They're only 12, 13, 14. Doesn't matter, they're still explorers.
0:27:37 > 0:27:42Everyone back home will be so proud of me,
0:27:42 > 0:27:45and I'm proud of me, too.
0:27:51 > 0:27:54Next time on Serious Explorers...
0:27:54 > 0:27:56darting endangered lions...
0:27:58 > 0:28:01..the record trek takes its toll...
0:28:01 > 0:28:02I'm staying here!
0:28:02 > 0:28:05..and living with an African tribe.
0:28:05 > 0:28:08I'm going to come back soaking!
0:28:08 > 0:28:11E-mail subtitling@bbc.co.uk