Lupo is out for a walk with Nanny and Prince George in Kensington Gardens when he is lured into a wicked trap. Cyrus the swan has been attacked, and some precious royal treasure stolen. Lupo is innocent but can he prove his innocence? Meanwhile, his rival, Vulcan the corgi is plotting to take over the realm. Animals take sides in a classic battle of good versus evil, involving journeys through underground tunnels, down the hallowed corridors of historic palaces, and in the staterooms of the most important people of the land. At the heart of this delightful story is the loyal bond between Lupo and the baby prince.