A tiny, nameless mouse with a question mark-shaped tail lives in the royal stables of Buckingham Palace. Embarrassed by his unusual tail and longing to know his true identity, he embarks on a daring adventure into the human world of Queen Victoria's court. With help from a mysterious cat and a retired cavalry horse, he navigates danger and discovers that even the smallest creature can have a grand destiny. This charming tale is a quest for self-discovery set against the glittering backdrop of Victorian London.