The Nazis have only recently been routed, but in England Fascism is becoming fashionable once again; the odious Sir Oswald Mosley has been vigorously recruiting members to his New Order of Britain party. Anxious to spoke his wheel, the secret service turns once again to Jethro, Cockney cat-burglar extraordinaire. They appeal to his pride, to his patriotism, to his preference for staying out of jail. Surely he wouldn't mind lifting a few vital documents from Mosley's headquarters? Jethro's an obliging fellow and the finest creeper in London, but larceny is never as simple as one might like to think.