Alison thinks that she is being haunted by the victims of the train crash which nearly killed her six years before. But she soon finds out that she is being followed by the survivors of the disaster, who want her to help them communicate with their lost loved ones. Robert and she come into contact with the afterlife in a way that will change their lives for ever.

• Stephen Volk

• Nikki Amuka-Bird
• Andrew Lincoln
• Harry Treadaway