Camilla, a kindhearted but not entirely competent young doctor, is training to become a psychiatrist. Having fallen under the spell of an enigmatic senior colleague, she is struggling to combine the demands of her job with pursuit of their illicit affair. After one of the patients in her therapy group takes a fatal overdose, Camilla gets involved in a tragicomic series of misadventures. With elements of satire, mystery and romance, Overdose has been described as giving a "gripping but shocking" picture of the dark side of psychiatric practice in 1980s England. Set in the forgotten world of a mental asylum, its medical background is largely authentic, but the plot and characters are fictional and not intended to be taken too seriously.