It's the first day of summer holidays and Finn can't believe his marine biologist mum is dragging him and his little brother Jesse off to miserable, rainy Scotland to study the whales that live there. Finn longs to be somewhere hot, lying by a hotel pool with his headphones on. He's sick of his mum's work, and of the knot in his stomach that tightens whenever he thinks about her hopeless cause - beautiful sea creatures endangered by a plastic-polluted ocean. But when a girl with binoculars round her neck and a dog at her heels takes Finn and Jesse to her secret lookout point, Finn soon finds himself swept up in an unforgettable adventure. But can he find hope too?