It is nearly Christmas and the Valley Villages are getting ready to enjoy the festive season. However, for the members of Spy Club, an intrepid band of animal investigators led by the Dawsons' Siamese cat, Jake, the excitement is interrupted by an unexpected occurrence. When the owner of one of the Spy Club members goes missing, the team are determined to discover what has happened to him. With help from Pa Dawson, the Club's new and only human member, they set about putting all their efforts into finding out where he has gone and what exactly is going on. With two successful investigations to their name, they feel sure that they will succeed in their enterprise. However, as their investigation progresses, they begin to realise that they have got involved with a situation far more serious and dangerous than they could have imagined. Over the course of their search for answers to the puzzle of Marcus's disappearance, several members of the team find themselves facing unexpected perils. It takes all their courage and ingenuity to bring the situation to a satisfactory conclusion, in time for them to enjoy the Christmas celebrations.