In April 2007, authorities boarded a drifting catamaran off the coast of Australia and found an eerily ordinary scene: a running engine, a powered laptop, a meal set out, and life jackets stowed, but no trace of the three-man crew. This episode investigates the Kaz II, a modern-day Mary Celeste mystery, and traces the final known moments of three cautious retiree sailors from Perth.

The discussion walks through a shockingly tight timeline, including a fishing vessel that passed within 50 meters without reporting the boat, and the forensic evidence that ruled out foul play. It then examines the chilling home video filmed hours before the crew vanished, the conspiracy theories it fueled, and the coroner's tragic chain-reaction theory of how a snagged fishing line put all three men in the water.

• The pristine, undisturbed scene that  ...