On an airplane bound for London from Paris, one of the 11 passengers is dead. The small red puncture wound on the woman's neck might have been accepted as a sting from a wasp, but luck is not on the killer's side. Hercule Poirot is aboard the plane, and he discovers a thorn typically used with a blowpipe near the victim's feet. As he tackles the case, suspicion points in all directions, even back to Poirot, when the blowpipe is found tucked behind his very own seat. Can Poirot prevent the culprit from getting away with murder?