The story begins when Mrs. Leidner, the wife of the archaeologist leading the dig, is found murdered in her tent at the dig site in Mesopotamia (modern-day Iraq). The site is remote, with the only people present being the members of the archaeological team and the local staff. Mrs. Leidner had been living at the site with her husband, Dr. Leidner, and several of the team members, including both British and local personnel.

Initially, it appears that Mrs. Leidner may have been killed by an unknown assailant. The murder takes place in the dead of night, and the tent is found locked from the inside, with no sign of anyone entering or leaving. There are several theories about how the murder occurred, and the mystery deepens when Dr. Leidner insists that his wife had been terrified of something or someone, but no one can figure out what she was afraid of.