A man falls in to private detective Richard Diamond's office on his last legs, handed him a sealed plain white envelope with no address on it and muttered the words Key West before falling over on his face very dead. Diamond hears someone moving around in the hall, scribbles the address of Lieutenant Levinson on the envelope and quickly leaves the apartment with the men on his heels. He manages to post the envelope before being done over by the men. Who are the men and why is the envelope so important to them? Listen as Richard Diamond solves the mystery.