Jessica Fletcher, a mystery writer and amateur sleuth, becomes involved in the investigation after a passenger is found dead on a flight she is taking. Her keen observational skills and intuition drive her to piece together the clues surrounding the murder.

The victim is a wealthy businessman named Roger Hargrove, who is found dead in his seat on the plane. His character is portrayed as arrogant and self-important, which leads to various suspects among the other passengers.

Jessica uncovers several key clues, including a mysterious note found in the victim's pocket, the behavior of the other passengers, and inconsistencies in their alibis. She also learns about Hargrove's contentious relationships with several individuals.

The other passengers exhibit a mix of fear, suspicion, and intrigue regarding the murder. Some are cooperative, while others are defensive or evasive, particularly as Jessica begins to ask probing questions that reveal their connections to the victim.

The flight's destination is significant as it ties into the victim's business dealings and personal relationships. The location becomes a focal point for Jessica as she investigates the motives of those who may have wanted Hargrove dead.