In the second book in the Lulu and the Dance Detectives series, Lulu and the Silver Star Dancers have been invited to perform at a pool party! Their synchronised swimming routine and sparkly mermaid costumes are all set to make a real splash … but things don't quite go according to plan. Mouse is terrified of putting her head under. The water is turning a very strange colour. Who is sabotaging the party? And why? Will the Silver Star Dancers crack this case? And can this birthday party be saved?