Medical examiner Dr. Harry Morgan (Ioan Gruffud) solves crimes by studying the dead but secretly hopes to figure out the mystery of his own immortality.
In the opening episode Henry dies in a subway crash and partners up with Detective Jo Martinez to solve the case of the subway crash.
Through flashbacks we see Henry during the slave trade and a world war. Henry becomes a suspect when Jo uncovers Henry was on the ill fated subway. Henry is being stalked by someone who phones him and teases him about his immortality. The person sends Henry a picture of himself and his true love Abigail which confirms that Abigail knew Henrys' secret.
It is revealed that the driver of the subway was poisoned and did not take a heart attack. Henry thinks the stalker poisoned the subway driver to prove he couldn't die. A finger print behind the drivers ear leads Henry and Jo to a house which is full of aconite. The suspect gets away but throws aconite over Jo's hand. Henry has to burn it off her hand to prevent it spreading.
Henry and Jo go for a drink and they speak about both of their pasts. The suspect is planning to sift poison through the air vents of grand central station. Jo is shot but survives and Henry pushes himself and the killer off the roof, killing them both. Henry goes to see Jo in hospital and he lies and says only Hanz fell off the roof.