THE MYSTERY OF THE MISSING H- BOMB PAPER

On the morning of Wednesday 7 January 1953, atomic physicist John Archibald Wheeler stood on his tiptoes on the lavatory seat of a Pullman sleeper train to Washington DC and peered over into the next door cubicle at another man doing his business.

Wheeler might well have asked himself what on earth he was doing. A happily married man, he risked being caught and labelled a sexual deviant. His prestigious position at Princeton, and his standing at the very top of the American scientific community, would surely be destroyed by the scandal that would ensue.

But at the moment of his Peeping Tom act, Wheeler had no thought for any of those consequences. His focus was not on the man sat on the toilet seat below, but on the wall next to him, where a manila envelope was tucked behind the pipes of the lavatory system. It contained nothing less than the biggest secret on the planet – and Wheeler had to get it back.

The absent-minded scientist had left it there on his visit to that cubicle just a