0:00:11 > 0:00:15Everything we've heard about the notebook is true.
0:00:15 > 0:00:20Many of this boy's designs are childish fantasy.
0:00:23 > 0:00:25But others...
0:00:27 > 0:00:30are magnifico.
0:01:07 > 0:01:09What was that?
0:01:09 > 0:01:10This is hopeless.
0:01:10 > 0:01:14We'll never find a secret chamber. These catacombs go on for miles.
0:01:14 > 0:01:17It would be amazing to map them properly.
0:01:17 > 0:01:19We won't find your notebook like this.
0:01:19 > 0:01:21Wait!
0:01:21 > 0:01:22A clue?
0:01:22 > 0:01:27Look. Silver denarius. Roman, I bet. No! Vespasian. Wow.
0:01:27 > 0:01:32- That's over 1,400 years old. - The rats have had two of my toes.
0:01:34 > 0:01:35Hang on.
0:01:35 > 0:01:36Look at this.
0:01:38 > 0:01:40Barely scratched.
0:01:41 > 0:01:43These are nearly new.
0:01:57 > 0:01:58Aargh!
0:01:58 > 0:02:00THEY LAUGH
0:02:01 > 0:02:03Very funny.
0:02:06 > 0:02:07Idiots.
0:02:10 > 0:02:11Boys!
0:02:11 > 0:02:16So, if X is to the value of four, to what value must Y correspond?
0:02:20 > 0:02:23Oh, cavelo! My spectacles.
0:02:27 > 0:02:32Oh, young master, if X is four, how on earth can Y be three?
0:02:32 > 0:02:33KNOCK ON DOOR
0:02:33 > 0:02:34Entry.
0:02:39 > 0:02:40My apologies.
0:02:42 > 0:02:45Something unexpected at the family business.
0:02:45 > 0:02:47Yes!
0:02:48 > 0:02:50Homework. Page 43.
0:02:50 > 0:02:52Abutre's elements.
0:03:00 > 0:03:02From this notebook
0:03:02 > 0:03:05we will conjure deadly weapons.
0:03:08 > 0:03:11And bring the Duke of Florence to his knees.
0:03:12 > 0:03:15Which, after all, is what we're here for.
0:03:17 > 0:03:22His notes are in code.
0:03:23 > 0:03:28Fortunately, we have among us Florence's finest mathematician.
0:03:28 > 0:03:31A man without equal in the world of equations.
0:03:31 > 0:03:33Professor.
0:03:35 > 0:03:39THEY SPEAK LATIN
0:03:44 > 0:03:45See?
0:03:45 > 0:03:48They must have been dropped recently.
0:03:48 > 0:03:50Maybe by one of the men who snatched Lisa.
0:03:51 > 0:03:54Lisa! Sorry. Tom, ciao.
0:03:54 > 0:03:57I found these in the catacombs. Was anyone wearing them?
0:03:58 > 0:04:00I couldn't see their faces.
0:04:00 > 0:04:02Sleep well?
0:04:02 > 0:04:05First mattress in four weeks. What do you think?
0:04:05 > 0:04:06You're...
0:04:08 > 0:04:09I'll have to cut it.
0:04:11 > 0:04:14Here. I can keep watch.
0:04:15 > 0:04:17Thanks. I'll do it later.
0:04:17 > 0:04:19- See if you can trace the owner. - Sure.
0:04:19 > 0:04:22Easy. Only 52 different lens makers in Florence.
0:04:22 > 0:04:24Specs are two a florin in the marketplace.
0:04:24 > 0:04:27- But you can't buy ivory in the marketplace.- Ivory?
0:04:27 > 0:04:30Been at work since dawn, have we?
0:04:30 > 0:04:32Claiming a well-earned rest?
0:04:32 > 0:04:34Thought not.
0:04:34 > 0:04:37Distracting my apprentices again.
0:04:38 > 0:04:41Master Lorenzo, my apologies.
0:04:41 > 0:04:43I hadn't realised we were graced by a Medici.
0:04:45 > 0:04:48Forgive me, I must reclaim my charges.
0:04:50 > 0:04:55Leonardo, canvas to complete. New boy, chance to prove yourself.
0:04:58 > 0:04:59Presto!
0:05:06 > 0:05:08- She's beautiful.- Thank you.
0:05:08 > 0:05:12But flattery is no substitute for talent.
0:05:12 > 0:05:14You have to prove your worth.
0:05:14 > 0:05:15I want to be able
0:05:15 > 0:05:18to reproduce her, life-size.
0:05:19 > 0:05:20From that.
0:05:23 > 0:05:25You want me to...
0:05:26 > 0:05:27..carve this
0:05:27 > 0:05:29from that with these?
0:05:29 > 0:05:31Oh, dear. Do you see a blade?
0:05:33 > 0:05:36No. This is a mathematical instrument.
0:05:36 > 0:05:38Mathematics?
0:05:38 > 0:05:40To map the proportions.
0:05:40 > 0:05:42You can count, can't you?
0:05:42 > 0:05:44Measuring isn't beyond you?
0:05:44 > 0:05:50- Then I carve it with... - Then you pitch it,
0:05:50 > 0:05:55with this, then you carve it, then I sculpt it.
0:05:56 > 0:05:59- Tomorrow.- Tomorrow?
0:05:59 > 0:06:03Don't forget, new boy, you're still on trial.
0:06:12 > 0:06:13How are we getting on?
0:06:13 > 0:06:16Excellency, I'm sorry, you surprised me.
0:06:16 > 0:06:17Well?
0:06:17 > 0:06:22I made an initial scan using Pythagoras. I've ruled out
0:06:22 > 0:06:25Pasolini's theorem and Duseka's model of transfer of decimals.
0:06:25 > 0:06:27There is alphabetically consistent
0:06:27 > 0:06:31- recurrence, but no logic... - You can't do it, can you?
0:06:31 > 0:06:37No... Yes, Excellency, of course I can, but these things take time.
0:06:37 > 0:06:38It's a process
0:06:38 > 0:06:42- of elimination. - It's a child's diary, Professor.
0:06:42 > 0:06:44Yes, Excellency.
0:07:04 > 0:07:05Tom.
0:07:06 > 0:07:09Think about it. It's three-dimensional.
0:07:10 > 0:07:12- Three di-what-imal? - It's called pointing.
0:07:12 > 0:07:16If you mark three fixed points in space, you can plot a fourth.
0:07:16 > 0:07:19Look. OK. Three points on the model.
0:07:19 > 0:07:22Head, two feet. Replot on the block here, here and here.
0:07:22 > 0:07:23If you want to know where
0:07:23 > 0:07:26her belly button goes,
0:07:26 > 0:07:28measure it in relation to three points here
0:07:28 > 0:07:30then do the same there. Big scale. OK?
0:07:32 > 0:07:33Grazie.
0:07:35 > 0:07:37It's all right. He's not here.
0:07:37 > 0:07:40Good news. Found an optician who sells ivory frames.
0:07:40 > 0:07:44It's very high-end. We'll need someone to give us an in.
0:07:44 > 0:07:46- Anyone in mind?- Let me see.
0:07:46 > 0:07:51How about the pampered teenage son of a wealthy and powerful nobleman?
0:07:53 > 0:07:56What do you think of my new suit? Can I pull off this colour?
0:07:56 > 0:07:59Definitely. Like you say, burnt orange is so now.
0:08:00 > 0:08:02OK. Here it is. You go in.
0:08:02 > 0:08:06- Keep him distracted while we look through the customers.- No problem.
0:08:09 > 0:08:14Signor Medici. Master Lorenzo, this is indeed an honour.
0:08:14 > 0:08:17Gilberto degli Specci, at your service.
0:08:17 > 0:08:19My servants, they can come in.
0:08:19 > 0:08:21They catch the cold easily.
0:08:27 > 0:08:31- What can I do for the young master? - I think I need my eyes tested.
0:08:31 > 0:08:33Of course, step this way, please.
0:08:35 > 0:08:37You have many customers, Signor.
0:08:37 > 0:08:40All of Florence's finest entrust their eyes to Gilberto.
0:08:40 > 0:08:43Now, can you read the letters in front of you?
0:08:45 > 0:08:46HE COUGHS
0:08:48 > 0:08:52A, E, Z, L, D, O,
0:08:52 > 0:08:55T, D, A, Ep.
0:08:55 > 0:08:59Master Medici, your sight is excellent.
0:09:02 > 0:09:04Oh! Can I try another one?
0:09:16 > 0:09:20- Haven't a clue. - Really? How interesting.
0:09:28 > 0:09:31Is it better with this or without?
0:09:31 > 0:09:35- With or without?- With.
0:09:36 > 0:09:37Gilberto!
0:09:38 > 0:09:41Professore, I am with a very important client.
0:09:41 > 0:09:43I've lost my new spectacles.
0:09:44 > 0:09:46Get out of the way!
0:09:51 > 0:09:53- Do you still want ivory?- Of course.
0:09:53 > 0:09:55I'm waiting for a shipment from Africa.
0:09:55 > 0:09:59- Is there nothing you can do? - Sorry, Signor.
0:10:04 > 0:10:05Now, where were we?
0:10:11 > 0:10:13With or without?
0:11:09 > 0:11:12I've been looking all over. Couldn't get away.
0:11:12 > 0:11:15I was desperate to tell you, that's poker-face Pico.
0:11:15 > 0:11:17- He's my maths tutor. - Your maths tutor?
0:11:19 > 0:11:21Is that what the optician gave you?
0:11:21 > 0:11:23He nearly saw me. They're useless.
0:11:23 > 0:11:26Could he be part of that weird secret society?
0:11:26 > 0:11:28Doubt it. He's way too boring.
0:11:29 > 0:11:30It's perfect.
0:11:35 > 0:11:36A magnescope.
0:11:45 > 0:11:47My catapult.
0:11:47 > 0:11:49And my code. He must have my notebook.
0:11:49 > 0:11:52Leo. Hold on. It could be dangerous.
0:11:52 > 0:11:55Scusi, Signore, Professore.
0:11:55 > 0:11:58Go away, boy. Whatever you're selling, I'm not interested.
0:11:58 > 0:12:00I have your spectacles.
0:12:00 > 0:12:02And you have something of mine.
0:12:02 > 0:12:03A notebook.
0:12:03 > 0:12:05Yours?
0:12:05 > 0:12:06Yeah.
0:12:06 > 0:12:09So you have the code.
0:12:09 > 0:12:13I didn't take your notebook. You must believe me.
0:12:13 > 0:12:15- I had no idea it was stolen. - Who did, then?
0:12:15 > 0:12:18I don't know. They blindfolded me.
0:12:23 > 0:12:26- Did they take you to the catacombs? - I don't know. Perhaps.
0:12:26 > 0:12:30They said if I didn't decode it by midnight they'd kill me.
0:12:30 > 0:12:33We must report them. They must be stopped.
0:12:33 > 0:12:37Please, I'm begging you. If we tell anyone, they'll kill me.
0:12:37 > 0:12:39And not just me, my family.
0:12:39 > 0:12:42My wife, my son - a boy your age.
0:12:42 > 0:12:46And my little girl, Fiameta, she's only six.
0:12:46 > 0:12:48I can't risk their lives. They're too precious.
0:12:48 > 0:12:51- What do they want with my notebook? - I don't know.
0:12:51 > 0:12:56If I don't decode your designs by midnight, that's it.
0:12:56 > 0:12:57If only...
0:12:57 > 0:13:01- No. I can't ask it of you. - You want me to give you the code.
0:13:01 > 0:13:05You're the only one who can save my little girl.
0:13:09 > 0:13:10OK.
0:13:11 > 0:13:13OK, I'll give you the code.
0:13:13 > 0:13:15Grazie. Grazie.
0:13:15 > 0:13:19Meet me in my rooms. 44 via Ventura.
0:13:19 > 0:13:21But come after dark.
0:13:21 > 0:13:22If anyone sees us...
0:13:29 > 0:13:31I don't trust him. Has he even got a family?
0:13:31 > 0:13:34I don't know. Hang on. Yes, he has.
0:13:34 > 0:13:37He cancelled my class. Said it was family business.
0:13:37 > 0:13:40How are you going to get across town after dark?
0:13:40 > 0:13:41You'll end up in prison if you get caught.
0:13:41 > 0:13:43I'm not going to get caught.
0:13:43 > 0:13:45Aristocrats don't get stopped.
0:13:45 > 0:13:48I can't go out after curfew. My father would kill me.
0:13:48 > 0:13:51It's OK. I'll find a way.
0:13:51 > 0:13:54If you insist on going, we might as well get you there safe.
0:13:54 > 0:13:56No-one would stop a priest.
0:13:56 > 0:13:59Let me see if I can find something.
0:14:01 > 0:14:02A priest?
0:14:04 > 0:14:07CHURCH BELL CHIMES
0:14:07 > 0:14:09That's it. That's the curfew.
0:14:09 > 0:14:11No going outside now, you lot.
0:14:26 > 0:14:28I can't do it!
0:14:32 > 0:14:33I hate this.
0:14:36 > 0:14:40I just want to paint.
0:14:43 > 0:14:44SHE SOBS
0:14:48 > 0:14:49I miss my mum.
0:14:52 > 0:14:54I want to go home.
0:14:57 > 0:15:00I've got a few minutes. I can help.
0:15:02 > 0:15:03There's no point.
0:15:04 > 0:15:06It's over.
0:15:10 > 0:15:11I'll come with you.
0:15:12 > 0:15:14I'll help you get across town.
0:15:17 > 0:15:19It's all my fault anyway.
0:15:19 > 0:15:22No, you can't risk being caught.
0:15:22 > 0:15:24I know how to dodge the night watchmen.
0:15:24 > 0:15:26I've slept on the streets.
0:15:26 > 0:15:29- I'll just get cleaned up. - It's not a good idea.
0:15:38 > 0:15:39Leo?
0:15:44 > 0:15:46Leo, where are you?
0:15:58 > 0:16:01CHURCH BELL CHIMES
0:16:16 > 0:16:18You have done your maths homework, haven't you?
0:16:18 > 0:16:21- Professor Pico didn't set any. - Really?
0:16:21 > 0:16:24He didn't. He cancelled, said he had family business.
0:16:24 > 0:16:28Lorenzo, enough. You're not even a good liar.
0:16:28 > 0:16:29Pico doesn't have a family.
0:16:29 > 0:16:33- Anyone can see the man's married to his maths.- What?
0:16:33 > 0:16:38Get on with it, or I'll have him set you double for the weekend.
0:16:42 > 0:16:43Hm...
0:16:53 > 0:16:55Halt! Who goes there?
0:16:58 > 0:17:00Sorry, Father, carry on.
0:17:08 > 0:17:10- Well?- Good news, Excellency.
0:17:10 > 0:17:13I need one number to complete the sequence.
0:17:13 > 0:17:17For that I must return home to consult the relevant tables.
0:17:17 > 0:17:20- You will have the code by midnight. - Midnight.
0:17:20 > 0:17:23- Without fail.- Oh yes, without fail.
0:17:24 > 0:17:29Professor, did you set the young master homework tonight?
0:17:29 > 0:17:30Always, Excellency.
0:17:46 > 0:17:47Not turning in?
0:17:49 > 0:17:51In a minute.
0:17:56 > 0:17:58KNOCK ON DOOR
0:18:01 > 0:18:03- Where's Leo?- What?
0:18:03 > 0:18:04Where is he?
0:18:04 > 0:18:06- Something terrible.- Pico's lying.
0:18:06 > 0:18:09- Leo's in danger.- It's a trap. - Leo's not here.
0:18:09 > 0:18:12Oh, no. He's going to give him the code.
0:18:12 > 0:18:14I'm coming with you.
0:18:14 > 0:18:18- She can't come. It's too dangerous. - Whatever.
0:18:18 > 0:18:19I've got to get back before my dad finds out.
0:18:19 > 0:18:23- You're not coming with me? - He's on my case, Mac.
0:18:23 > 0:18:24You don't understand.
0:18:27 > 0:18:29Where are we going?
0:18:54 > 0:18:56Fantastico!
0:18:56 > 0:18:57I see you're impressed.
0:18:57 > 0:19:00Everything I love is in this room.
0:19:00 > 0:19:04Algebra, theorems, calculus, trigonometry.
0:19:04 > 0:19:06Nothing else matters. Right?
0:19:10 > 0:19:12And your son, does he come in here?
0:19:13 > 0:19:16Hm? Oh, Alfredo? Of course.
0:19:17 > 0:19:20- Wow! - The hours we spend here together.
0:19:21 > 0:19:23He's the image of you.
0:19:23 > 0:19:27Brilliant, curious. I'd love you to meet him.
0:19:27 > 0:19:29If I can get out of this.
0:19:30 > 0:19:33I may never see Alfredo again.
0:19:33 > 0:19:36Or Francesca. I need that code.
0:19:36 > 0:19:37I'm desperate.
0:19:41 > 0:19:45Don't worry, I will not let your children die.
0:19:45 > 0:19:48DRAMATIC MUSIC
0:19:56 > 0:20:01Thank you. We're scientists. We share a bond, don't you think?
0:20:21 > 0:20:25- Halt!- I've got no money. All I've got is the shirt on my back.
0:20:29 > 0:20:32Of course. The Fibonnaci sequence
0:20:32 > 0:20:35as inverted matrix. How stupid of me!
0:20:35 > 0:20:37I'd have got there in the end.
0:20:39 > 0:20:41I'm sorry, truly I am,
0:20:41 > 0:20:45but I can't risk my leader finding out how I got the code.
0:20:45 > 0:20:50But the Luminari will always be grateful for your designs.
0:20:50 > 0:20:53Your leader? The...Luminari? Who are you?
0:20:53 > 0:20:56You won't live long enough to find out.
0:20:57 > 0:20:59Leo! Open up!
0:21:19 > 0:21:23- Now is not the time to say I told you so, Leo...- You're right.
0:21:38 > 0:21:39CHURCH CLOCK CHIMES
0:21:40 > 0:21:44Midnight. Saved by the bell. For now.
0:21:44 > 0:21:47But I know where you live, boy.
0:21:57 > 0:22:00Was I too late? Did you give it to him, the code?
0:22:06 > 0:22:08Bear with me, Excellency.
0:22:08 > 0:22:10It's a matter of the correct column.
0:22:10 > 0:22:16The sequence isn't quite transmitting the way it should.
0:22:16 > 0:22:19I'm not sure what he's done. Just give me a moment.
0:22:19 > 0:22:23I'm sorry, Professor. We've no place for amateurs.
0:22:25 > 0:22:27Goodbye.
0:23:00 > 0:23:03MUSIC: Someone Watching Over Me by The Zutons
0:23:13 > 0:23:14DOOR OPENS
0:23:23 > 0:23:27# I'm gonna wait alone under my sheets
0:23:27 > 0:23:31# And pretend to close my eyes
0:23:31 > 0:23:35# And I will wait until the sun comes up
0:23:35 > 0:23:39# I will wait all night
0:23:39 > 0:23:43# I don't care if you don't come and show yourself
0:23:43 > 0:23:46# Cos I know you're always near me
0:23:46 > 0:23:51# And when it's dark again I'll count to ten
0:23:51 > 0:23:54# And you'll be standing by me... #
0:23:55 > 0:23:56How did you know it was a trick?
0:23:57 > 0:23:58In the cafe he called her Fiameta.
0:23:58 > 0:24:01And my little girl, Fiameta.
0:24:01 > 0:24:04Then he forget, he called her something else.
0:24:04 > 0:24:06I may never see Francesca again.
0:24:06 > 0:24:08But something was off.
0:24:08 > 0:24:11He said everything he loved was in that room.
0:24:11 > 0:24:13Yet there was no sign of his family.
0:24:13 > 0:24:15He didn't seem like a dad.
0:24:17 > 0:24:19So you gave him a fake sequence?
0:24:19 > 0:24:21Of course. It had to be good enough to believe.
0:24:21 > 0:24:26By the time he got to his leader, half the alphabet would be missing.
0:24:27 > 0:24:30So Florence's top mathematicians couldn't crack your code?
0:24:31 > 0:24:35Good. Means they can't use your designs.
0:24:35 > 0:24:37KNOCK ON DOOR
0:24:37 > 0:24:43Yes? Ah, Lorenzo. Sad news, I'm afraid.
0:24:43 > 0:24:45Professor Pico has left us.
0:24:45 > 0:24:49Yes, he's had to leave Florence on personal business.
0:24:49 > 0:24:51Unexpectedly.
0:24:52 > 0:24:55He won't be coming back.
0:24:55 > 0:24:59Great. Father, you've cut yourself, on the left.
0:25:02 > 0:25:04You mean my right. Thank you.
0:25:09 > 0:25:10Of course!
0:25:12 > 0:25:13Backwards.
0:25:15 > 0:25:17It's written
0:25:17 > 0:25:18backwards.
0:25:21 > 0:25:24HE LAUGHS
0:25:28 > 0:25:32- Maybe you should tell your dad about the Luminari.- I can't.
0:25:32 > 0:25:35If he knew I hung around here... Besides, he'd never believe it.
0:25:35 > 0:25:38And with Pico gone, so has any chance of us finding out.
0:25:38 > 0:25:41- And your designs, all that research lost forever.- No.
0:25:41 > 0:25:44No way. I'll redo them, everything.
0:25:44 > 0:25:50- Whoever they are, they are not going to stop me.- Yes!
0:25:50 > 0:25:52Come on. I'll do it.
0:25:52 > 0:25:55No point. After the mess I made of that stone,
0:25:55 > 0:25:58I won't be here much longer.
0:25:58 > 0:26:02Good morning, Master Lorenzo. You two, inside.
0:26:10 > 0:26:14A mess. One long catalogue of errors.
0:26:17 > 0:26:20Judging from the way you stayed on your feet,
0:26:20 > 0:26:23plugging away until dawn.
0:26:23 > 0:26:24HE CHUCKLES
0:26:26 > 0:26:27You want to learn!
0:26:29 > 0:26:31It's all I needed to know.
0:26:40 > 0:26:42SHE LAUGHS NERVOUSLY
0:26:49 > 0:26:51- Come on.- Wait!
0:26:54 > 0:26:58My mum used to brush it every morning for as long as I remember.
0:27:02 > 0:27:04OK, just do it.
0:27:07 > 0:27:09Stop! Don't cut it.
0:27:11 > 0:27:13What?
0:27:20 > 0:27:22Oh-ho!
0:27:23 > 0:27:25THEY LAUGH
0:27:55 > 0:27:57Subtitles by Red Bee Media Ltd
0:27:57 > 0:27:58E-mail subtitling@bbc.co.uk