Gavin is uncomfortable with Gwen and Bryn knowing about his and Stacey's sex life.
Luther has a copycat killer on the loose, a body to hide and a suspicious Baba to appease.
Pam Ferris makes an impassioned appeal on behalf of The Princess Royal Trust for Carers.
Luther must save Ripley's life in time to stop Cameron's final murderous set piece.
Gavin starts his new job in Cardiff, while Smithy tries to adjust to life without him.