A field trip to the local art museum with Mittens's rambunctious nieces takes an unexpected turn when a priceless Monet painting is stolen! With their reputations on the line, the museum leadership desperately turns to Mittens and Alex for help. Will the detectives see past the deception around them to discern friend from foe? Could this be another crime organized by the mysterious Ruffled Feathers? Most importantly, can the museum survive the antics of the crazy Kastle kittens?