Dr Lanning, Catherine Stannard and Patrick Hawton are thrown together by a motorway tragedy. Dr Lanning is treating Catherine and Patrick for PTSD, the loss of their loved ones, their different approaches to feeling and dealing with survivor guilt. Through shared therapy sessions, Catherine and Patrick form a bond, allowing them to relinquish their previous lives and inhibitions. Dr Lanning sees an opportunity to study them, using them to rebuild his reputation. In doing so, he creates an environment where Catherine and Patrick begin to lose sight of their new realities.