SPUD - the Super Perceptive Undercover Detectives - are on holiday, but find themselves in a race to solve a new mystery! When Callie, Grace and their Spy in the Sky - mynah bird Bo - discover puffins coated in waste oil that has been dumped in the sea, they must find out who is to blame. Can they crack the case before more damage is caused to precious sea life and the Welsh coastline?

Complete with wonderful black and white illustrations from Louise Forshaw