When twelve-year-old Rixon's great-uncle leaves him the mysterious Splinter Island in his will, Rixon can't quite believe it. There's only one thing to do -- go there and see it for himself. Alone. And Splinter Island might just hold the key to the future of the planet, in the form of four children hidden away from society. But soon Rixon and the others are fighting for their lives - left in a cave with a rising tide, floating out to sea on a leaky inflatable, and fending off the attacks of a famous tech giant and his enormous silver yacht.