Fay McMahon, a nurse to Mrs. Mary McLeavy, who died three days before the action of the play. Fay is a femme fatale, a mercenary who will do anything for money. She convinced Mrs. McLeavy to change her will, leaving everything to Fay. Her seven husbands in the past decade all died violently, and she has poisoned her patient. When she learns that Hal and Dennis have robbed a bank, she demands a third of the spoils and decides to marry Dennis now that he is rich.
McLeavy, Fay’s employer, a devout Catholic. A self-proclaimed good man, he insists that his wife was precious to him, but he has devoted most of his attention to his roses. He at first refuses to believe that his son is a bank robber, then wants to disown him, and finally is willing to testify against him. He respects authority and tries to cooperate with Truscott’s investigation, only to be arrested for making derogatory remarks about the police.
Hal McLeavy, the only child of the McLeavys. Burdened by Catholic guilt, he worries about committing some unforgivable sin yet deflowers virgins and steals from slot machines. He hopes to use the proceeds from the robbery to open an extravagant brothel. His upbringing makes him incapable of lying, and he readily confesses to Fay and Truscott.
Dennis, Hal’s young friend, an undertaker’s assistant. A ladies’ man who has impregnated five young women, he longs for the experience a woman such as Fay can offer. In charge of the funeral, he switches the stolen money and Mrs. McLeavy’s body between the coffin and a wardrobe in the McLeavy house. Dennis saves the coffin when a fiery accident occurs on the way to the funeral, and he also eliminates the evidence (the deceased’s stomach) of Fay’s poisoning.
Truscott, a police inspector. Flamboyant and sneaky, he investigates both the bank robbery and the poisoning while pretending to be from the water board. He assaults Dennis for denying knowledge of the theft and beats Hal for telling the truth. Truscott has followed Fay’s crimes for years and traps her into a confession. After tormenting the suspects, he accepts a bribe of 25 percent and arrests McLeavy, the only innocent person around.