Emily and Alexander's cousin Simone lives on a sugar plantation in Trinidad. When the two visit her, they arrive just in time for Carnival, which is celebrated in a big way here. Cousin Simone also has a splendid costume, which includes a precious necklace. It is precisely this necklace that Notail Nodoodnik, the deceitful rat, is after. And then there is someone else who is making life difficult for our mice: the Midnight Robber, a legendary figure who is up to mischief in the sugar cane fields. Our two detective mice immediately sense that something is wrong here.