Lucy is trying to help her son Isaac who seems to be suffering an emotional disorder. She's also having nightmares that wake her the same time every night. Meanwhile, DI Dhillon is investigating the murder of an elderly man in his home.

Lucy and Dr Bennett try hard to connect with Isaac, with little success, as his behaviour becomes more disturbing. DI Dhillon and DS Holness search desperately for the right Lucy Chambers, realizing too late they're after the wrong target.

Lucy and the police search frantically for Isaac. Lucy visits Mrs Slade, making a discovery that sends the investigation in a shocking new direction. Lucy's mother does something amazing.

Lucy exploits her connection with Dhillon to track down an elusive teenager, worried he is being targeted by their prime suspect.

Following a tragic twist of fate, Dhillon teams up with Lucy to track down the mysterious stranger at the centre of the chaos.