When veteran detective, Danny Frater (played by James Nesbitt), turns up at a hospital mortuary for what he thinks is a routine ID check on a young woman’s body, he gets a devastating shock; the corpse turns out to be his estranged daughter, Christina (played by Imogen King). Danny is traumatized by the news that according to the post-mortem report, she’s taken her own life. Danny and Christina had a complicated father-daughter relationship in recent years, but he refuses to accept that she would have ended her own life. He sets out on a mission for the truth, retracing her last days and hours, in an agonising crusade to discover what really happened to his only child.