Sherlock Ferret and his well-whiskered friend Watson Mouse M.D. visit the Museum, where they look at many paintings, including the famous Ferret Before a Mirror, by Pablo Pigasso. Sherlock discovers that, though it is meant to be an old picture, the painting in the Museum is new! What is the secret of this, and the other paintings by Pigasso? Sherlock and Watson investigate, together with their rhinoceros friend (although he is not very big) Lestrade. They talk to Moriarty Magpie and other nefarious characters, and Watson spends a very uncomfortable time in Pigasso's house before the answer is discovered.