Wally Carter, the obnoxious husband of a millionaire, is killed during a picnic. The case seems completely ordinary to the experienced Inspector Hemingway, because many people had a motive to get rid of Wally - his wife, her longtime admirer, stepdaughter, pupil, and even a guest at home. However, very soon the inspector establishes that none of the suspects had either the time or the opportunity to use the murder weapon. Literally everyone has an alibi. So which of the guests is lying?