December 1939. Germany and Great Britain are in the fog of the phoney war. The First Sea Lord Winston Churchill knows that England is not nearly ready for the fight. Four British spies have perished in strange circumstances in Nuremberg trying to discover the biggest secret of the Third Reich. Churchill turns to the only man he knows who can solve the mystery. But Lord Sherlock Holmes is now 83, Dr Watson even older. Are they still up to it? They must cross the Channel, pretend to be German sympathisers. If caught, England will disown them. Holmes accepts the challenge; indeed he has been awaiting the call. They will solve the mystery, or die in the attempt. Two ancient men of England and one beautiful nurse enter enemy territory. Their loyalty will be tested, more than once, and there is no one they can trust. The secret of Nuremberg is far more sinister than even Holmes could imagine; their chances of getting back alive, very slim indeed.