Aquí hay Gatson encerrado (Perrock Holmes, 5)

Julia absolutely adores Laura Sparks, and when she learns that the super-famous singer is auctioning off her diamond tiara, she's determined to attend. However, during the auction, someone steals the tiara... and, as if by accident, they take Gatson with them! Here are the facts: the tiara was last touched by a pair of magicians who performed the worst tricks ever. Here are the clues: it can't be magic...