The fourth “Adventure Island” book starts at Bosgoose Wood, where Emily, Scott, Jack and Drift, Emily’s dog, are exploring. They see five Braithwaite Boys’ School jeeps arrive on the heath for a camping trip. It gives Emily the idea to go camping but Aunt Kate (Scott and Jack’s great aunt) and Emily’s parents say no. Soon, though, something happens to take their minds off the disappointment: the police come to Stone Cottage! The two police officers say that a boy has gone missing, and as they were seen in the area, which is Bosgoose Wood, they are taken to the police station to be interviewed. Emily finds out that the missing boy’s name is Sam Chambers and the friends start investigating.
Some guests arrive at the lighthouse, which is ran by Emily’s parents as a Bed and Breakfast: Nico, Rudi and Anya. One night, though, Emily finds out that they are not the ordinary German group they seem to be when she sees Nico pick up a gun, when he hears a noise while talking with Anya and Rudi at 3 o’clock in the morning! Emily feels the “German Gang”, as she now calls them, have something to do with Sam Chambers’ disappearance.
What are the German Gang up to and is Sam Chambers just an ordinary schoolboy or is there more to him than meets the eye?