The dishonest duo - now well on their way to wealth with their 'company', Guaranteed Securities Inc., and a luxurious office - open another box, to reveal the secrets of a planned horse-racing coup. Needless to say, they tip the odds in their own favour!

Continuing to make a shaky living from their haul, Turtle and Eddie encounter the profitable world of antiques - along with some very tough opposition in the form of Pierre Sablon, an international double-dealer with a plan to rig a forthcoming auction.

Another box is opened, containing a chemical formula and a packet of synthetic tea. While a large American company, along with its hired heavies, has more than a passing interest in the tea, Turtle and Eddie are more taken with a box of car registration documents.

A new box yields top-secret documents, the property of an eminent, recently deceased Russian diplomat. The papers turn out to be a very hot potato, sought by British military intelligence, the German secret police... and Supt. Rafferty.

Turtle and Eddie have to move their hoard of deposit boxes when a disgruntled informer, Hermann the Torch, puts the police on their trail - but some forged credit cards and a rigged computer send them on a pantechnicon-sized spending spree.

The pair find they need the help of more than their accountant when they are investigated by the Inland Revenue. Supt. Rafferty, meanwhile, is under mounting pressure to track down a particular deposit box - one belonging to the Comissioner's brother, Sir James Brent.