In the cheerful, grubby backstreets of Soho, Jessie Milk finds herself a most unsuitable occupation as a receptionist in a hotel frequented by unsuccessful variety artists. Among the hotel's regulars is a dyspeptic conjurer with a plain wife and pretty assistant, both of whom drive him to distraction and encourage his professional and lethal tendencies . . .

Miss Milk confides her troubles to a retired Merchant Navy captain, now employed as a store detective. Combining their resources they are pursue the murderer in the bustle and crush of Coronation week.