Bertha Cool is very much a part of the seamy world of Bats Fly at Dusk.

She is greedy and unintelligent. A mean 165 pounds (she once weighed 285), she has broad shoulders and a nasty enough temper to use her size to intimidate people. Blundering from one clue to the next, her interest is in gaining a share of any insurance payment to Josephine Dell or of an inheritance left by her recently deceased boss Harlow Milbers. Solving the mysteries of Milbers's death and of the shooting of the thoroughly slimy Jerry Bollman only interests Cool insofar as the solutions can help her make money.

Her partner Donald Lam has joined the Navy at the outbreak of war between Japan and the United States. The brains of the team, he helps Cool with telegrams from San Francisco, where he is based. It is he who arrives on leave in...