For Aiden, Chloe, Ava and Josh, holidays at their grandparents' cottage mean wild beaches, no curfew, Bella the dog, and most of all - adventure! A picnic at a stately home takes a suspicious turn when the cousins discover a jewel heist unfolding around them. But how can they take down a gang of clever thieves when all they've got is their bikes and a very risky plan? By being braver, smarter, and sneakier than the villains they're chasing. . . Fleur Hitchcock is famous for her excellent "thrillers for beginners". This action-packed series takes 7+ readers on fantastic, realistic adventures. Cover illustration by Tom Clohosy Cole. Don't miss the other Clifftoppers adventures! The Thorn Island Adventure The Fire Bay Adventure The Frost Castle Adventure Look out for Fleur Hitchcock's stories for older readers: Dear Scarlett Saving Sophia Murder In Midwinter Murder At Twilight The Boy Who Flew