It starts quite innocently on Fifth Avenue on a cheerful autumn day . . . and all because a young physicist, Evans Parten, happens to meet an attractive girl, Alison Kent, and invites her to lunch with him the following Saturday.

He rings her doorbell on schedule, but the redhead who answers denies ever having seen or heard of Alison Kent. Evans concludes that he has been stood up. But while brooding in his car opposite the apartment house, who should come out but Alison, walking close to a dark-haired man who looks as if he may be holding a gun in his coat pocket. Losing their trail, Evans reports the matter to the police and, indeed, it develops that something is up and some very tough eggs are involved in it.

A breathtaking Lockridge chase follows with the panic-stricken girl, Evans, two engaging Manhattan detectives—and the reader—careening down a deadly path from a warehouse on the upper East Side to a freighter docked downtown; while murder, with a Spanish accent, stalks through a night of shadows.