A beautiful society woman is found dead, covered only in gauze, her body staged and lit up in a macabre tableau, in a beachfront summer house as a country club dance is in progress. Two young men stumble upon her, while a curious Tam O'Brien finds herself shortly on the scene. The local coroner, not well-acquainted with murder, welcomes her aid in a professional capacity: Tam o' Shanter, private detective. Motive and opportunity are complicated by clues pointing to a local drug operation, and Tam finds herself in a deadly situation as death strikes once again.

Tam O'Brien, as a young female detective, breaks more than a few of the literary cliches of Golden-Age Detective Fiction. She is smart, capable, well-trained, and unsusceptible to the allure of passing romance if it's going to get in the way of her job. Her father, Rance O'Brien, is an ex-Chief of Detectives on the police force, so she grew up surrounded by officers and detectives. Inspector Pete McCoy is an old friend, willing to discuss and debate a case, though not above a little friendly competition. Dips is the young, streetwise lieutenant of her inquiry agency.

The Jekyll-Hyde Murder Case was published as a magazine novel in 1930.