Chester, 1756: Mary Helsall starts a job as a nurse, entering a world of stench and sickness where her caring duties are at odds with her impatient nature. She seeks solace in gin and a volatile relationship with hospital porter Anthony. But when a diseased beggar arrives for treatment, it becomes clear that he knows Mary has a lot to hide. From the bleak Wirral shore to the screams of the operating theatre, and from a backstreet gin shop to the dungeons of the gaol, Mary searches for the hope of an independent future. First, though, she must fight the attraction of oblivion and make a choice between duty, money and a love overshadowed by addiction.