This in an intellectual locked-room whodunit with a psychological edge. The story centers on the mysterious death of Arthur Pendelton, a wealthy, retired linguistics professor. Found dead in his locked study, the lack of physical clues and the airtight alibis of his three prime suspects leave the police ready to rule it a natural heart attack. However, the murder has one traumatized witness: Pendelton's pet parrot, who is tearing out its own feathers in terror.