"Scars and Nightmares" is the first special episode in the 28th series of Casualty. It was directed by Dafydd Palfrey and written by Asher Pirie, and aired directly after the episode "Badge of Honour".
Iain has received a request to visit a fellow former soldier with whom he served and he persuades Sam to accompany him to the hospital where he is being treated. They are surprised to discover that he is not in a veterans' hospital but at a rehabilitation centre for veterans suffering from post-traumatic stress disorder (PTSD). As they are forced to confront the realities of this destructive condition, Sam and Iain find the experience deepens the bond between them.