Driven to desperate measures, nurse Cath Hardacre assumes the identity of her best friend, an A&E doctor and finds work in a struggling emergency department. It is not long before her lie threatens to unravel other areas of her life.

Buried in her stolen identity as Ally, Cath finds herself falling for Andy. But how can she keep hold off the perfect man when she is living a lie? An encounter with someone from her past threatens to expose her secret.

Following his discovery, Andy has a decision to make, whilst Ally faces the consequences of her deception during a weekend away with him. A fatal error at work backs Ally into a corner: does she protect her own identity or fall further into the lie?

Pushed to the brink, Ally’s personal life and medical career begins to fall apart. Karl heads up to Edinburgh and is desperate to take Molly back to Sheffield. But will Ally find a way of stopping him before it is too late?

When Jamie McCain arrives on the spinal unit he’s angry, uncooperative and refuses to talk about his injury. But what really happened to Jamie, and is he a man we can trust?

Jamie continues to disrupt the unit with his recurring night terrors. As he obsessively searches for the truth his behaviour becomes increasingly erratic. Is the threat real or imagined?