Jesse James may have made train robbery a world-famous American institution, but it took Johnnie Rainbow, a Briton, to pull off the world's greatest heist. Johnnie Rainbow is the code name assigned to the mastermind of England's $7,000,000 mail train robbery in 1963. He's still loose with most of the loot, though a dozen of his co-conspirators are behind bars. Or were -- for there was a recent daring raid on a maximum security cell during which the escape of one train robber was effected. The robbery, police developments, trial of the prisoners, and speculations about the present whereabouts of the money are rehearsed here by ex-police inspector Gosling, who claims to have talked with Johnnie Rainbow. For legal reasons, Gosling can't unmask the real Rainbow's identity, but he does give a thorough review of the mastermind's history. Rainbow had a bleak childhood as an orphan, later served the King with distinction, but was cashiered out of the Royal commandos for theft. The money was deposited in a foreign embassy in London for diplomatic transfer to a minor, sterling-needy country. The whole business was quite daring and, you guessed it, they're making a movie of it.