Tiger Standish travels back to London having decided, since he had been 'retired' from Y-1, to start up his own Intelligence agency. Right away he will find himself deep into a matter which will in short order pit the experienced Standish against the notorious foreign spy and villain known as the Disguiser. Standish's desire to capture this man changes to vengeance when he learns of the murder of his old friend and mentor, Sir Harker Bellamy.