London, 1974. As Britain prepares for electrical blackouts to sweep across the country, trainee nurse Val arrives for her first day at the crumbling East London Royal Infirmary. With most of the patients and staff evacuated to another hospital, Val is forced to work the night shift, finding herself in a dark, near empty building. Within these walls lies a deadly secret, forcing Val to face both her own traumatic past and deepest fears.
In the dark heart of a sprawling, anonymous city, two assassins carry out a sinister mission, a teacher battles a fatal illness, and an enigmatic janitor and a curious waitress lead dangerous double lives. Murderous consequences unravel in the dead of night, as their lives intertwine at the hands of a mysterious criminal mastermind who is hell-bent on revenge.