When Sarge sees a ghost in one of the exhibits during his night watch at the Baker Street Bazaar waxworks exhibition, everyone tell him he must have imagined it. But the ex-army officer is adamant, and when his job is put on the line as a result, Wiggins and Beaver decide to spend the night there themselves to find out once and for all what it was that he saw. When they do, they realize that all is not as it seems. Suddenly the Baker Street Boys are catapulted into a mystery involving a Russian spy ring, a case of mistaken identity . and murder.