An old "urban legend" stemming from an incident at the 1893 Paris Exposition is the inspiration for this episode. While visiting London, Jessica (Angela Lansbury) comes across a corpse in her hotel room. She summons the authorities, only to find that the corpse has disappeared--and subsequently, virtually everyone, including the police, adamantly insist that there never was a body, and that Jessica is merely imagining things. Ingredients essential to this intriguing yarn are a double espionage agent, a Scotland Yard detective, a slimy concierge, and a brazen "tart". ~ Hal Erickson, Rovi