A well-dressed man is found dead on an Adelaide beach in 1948, every label cut from his clothing, an untraceable poison in his system, and a scrap of Persian poetry sewn into his trousers. For more than seven decades, the Somerton Man baffled global authorities and fueled Cold War spy theories. This deep dive follows the trail from a pristine, staged crime scene to the modern DNA breakthrough that finally gave him a name.

We unpack the forensic puzzle piece by piece: the cardiac glycosides that vanish from toxicology screens, the hidden 'Tamam Shud' code, the unbreakable cipher, and the nurse who fainted at a plaster bust of his face. Then we trace how genetic genealogy, built from a few hairs caught in police plaster, dismantled the espionage myth and revealed a far more human and tragic truth.

• Why a perfectly balanced cigarette ...