Answer:
A week's vacation by the sea, with Holly's aunt! For the Mystery Club, there is no longer any question of playing detectives. One word on the agenda: idleness! Yes, but as soon as they arrive, Tracy notices something strange. In the middle of the bay, opposite the house, there is an island forbidden to the public: experiments were carried out there during the last war and the place is still dangerous. So how do you explain that Tracy saw lights there? Or rather, light signals. In fact of a quiet vacation, here are Holly Tracy and Belinda again on the warpath. As usual, adults don't take them seriously. However, it is a big, very big fish that they have just hooked. Of the bloodthirsty shark type, eater of overly curious teenage girls.
The mystery club - the forbidden Island is written by Fiona Kelly.
