Haunted by the death of a witness under his protection, when former policeman Robert moves to the Lake District, he is given a chance to redeem himself by safeguarding a family under threat.

The police have a possible connection between Sam Blackwell and known criminal Michael Collersdale. Robert explores the current theory, determined to get to the truth.

Ali receives devastating news and Robert has some difficult questions for her. Ali then takes an impulsive decision and Katy questions Robert's methods.

The investigation into Michael Collersdale takes an unexpected turn. Robert has some worrying news for David and Ali. Sam and Joe are caught up in a terrifying ordeal.