Dr Ruth Hartland rises to difficult tasks. She is the director of a highly respected trauma therapy unit. She is confident, capable and excellent at her job. Today she is preoccupied by her son Tom's disappearance.

So when a new patient arrives at the unit - a young man who looks shockingly like Tom - she is floored.

As a therapist, Ruth knows exactly what she should do in the best interests of her client, but as a mother she makes a very different choice - a decision that will have profound consequences.