Ex-con Kit Fraser, after six years of marriage to Barby and a steady job-ironically enough selling burglary insurance in his father-in-law's firm, is still serving a sentence- the fear of exposure, since only Barby knows his past. Until Kline turns up, a disbarred lawyer who has also done time, and blackmails Fraser and forces him to participate in a big job- the robbery of a wealthy woman whom Fraser has insured and thereby knows the ""special conditions"" (locks, alarms, etc.) of her policy. With a third man, Drummond, the jewels are lifted, and while Fraser wants no part of the take, Kline's plan to make away with all of it leads to murder- Drummond's. Kline gets away- and Fraser is on the run, until Barby gives him the courage to turn in a full report.... MacKenzie, with a fifth entry on his literary record, again uses the world he once knew to good advantage and handles this kind of case efficiently, excitingly.