Yasmin, Chloe and Will always seem to be investigating something on the school playground - today it's dozens of discarded cicada shells.

But when a mysterious lady in a big floral sunhat turns up, it turns out they're the ones being observed... but why?

Is their teacher Mr Barbossa being spied on? Is she investigating the magical properties of cicada shells? And who is going to lose a limb by the end of the book??

Find out all the answers in "The Cicada Detectives!"