A missing payroll and a rising death toll at a remote New Zealand hospital draw Inspector Alleyn into a complex web of suspicion. Mr. Glossop, delivering wages to Mount Seager Hospital, finds himself stranded and witnesses a payroll theft from a locked safe. As the hospital's mortality rate escalates beyond normal, the presence of an English detective involved in counterespionage raises questions about whether his arrival is a coincidence or a sign of a deeper conspiracy. Alleyn must navigate the isolated setting and the tensions between recovering soldiers and the nursing staff to uncover the truth.

This novel, completed by Stella Duffy from Ngaio Marsh's wartime manuscript, offers a classic mystery framework within a unique historical context. The premise suggests a slow-burn investigation, typical of Marsh's style, focusing on character interactions and atmospheric tension within the isolated hospital setting. The blend of a wartime espionage element with a seemingly contained hospital mystery provides layers for the reader to unravel. The completion by Duffy indicates an effort to honor Marsh's original intent while bringing the story to a modern audience.