Everyone talks about how powerful the oceans are, how huge, how mysterious, all those underwater creatures living down there in the deep. But they've got no one to stand up for them! Olivia Alez is loving her life away from the royal palace. Now she isn't a princess anymore she's even more determined to be a science investigator, finding out things about the world around her. When she goes to visit her uncle Cassander for a holiday, she realises there's a huge problem. The oceans are filled with rubbish, and she can't see any fish swimming about. They're nothing like the bright blue seas full of life that she's seen before. When Captain Max and his parrot turn up, Olivia and her best friend Ravi decide that getting on board their pirate ship as they hunt for treasure might be a good way to find out what's going on in the water. But they quickly realise that they've got more to discover than they ever imagined . . .