The Crimes of Stephen Hawke opens at a BBC radio studio, where a variety program is being broadcast. After the singing duo of Flotsam and Jetsom and a comic butcher perform, Tod Slaughter appears as himself to perform a radio play about Stephen Hawkes. Hawkes is, to all appearances, a model of kindliness and decorum. A money-lender, he is compassionate and caring toward his clients, and extremely attentive to his lovely daughter, Julia, whose beauty and innocence make her attractive to many suitors. But Hawkes is not all that he appears. In his guise as The Spine Breaker, he is a merciless and notorious murderer, viciously killing his victims in a gory and painful manner. Aided by his assistant, a strange hunchback, the first killing the audience sees involves an obnoxious but otherwise undeserving child. Eventually, Hawkes even kills his best friend; when the friend's son, Matthew discovers the truth, he vows to hunt down Hawkes himself.