Michael Marshall, a wealthy and obviously unscrupulous industrialist, is murdered. A short time later, his widow, Jill, comes to see Dr. Daniel Cooper, a psychiatrist, ostensibly to help her overcome her depression resulting from her husband's murder. Jill expresses doubts to Dr. Cooper, and eventually to Captain Jack DeAngelis, head of the homicide division, as to whether Michael's death was murder with robbery as the motive. Initially, no one suspects that Jill, an attractive woman of apparent refinement, could be guilty of duplicity in the murder. Through many twists and turns, including the murders of Marshall's accountant and private banker, the involvement of the mob, and the smuggling of drugs, the involvement of Jill becomes clear. Her sociopathic ability to worm her way out of this dilemma fools even the best detectives, but perhaps not the most cunning reader? Jack Be Quick is a murder mystery as well as an intriguing study about the complexities of the human mind.