Cymbeline (yes, really!) has never been swimming - not ever, not once - so he's a bit nervous at the prospect of his first school swimming lesson ever. But how hard could it be? He's Googled front crawl and he's found his dad's old pair of trunks. He's totally ready for this. But he's not ready for an accident at the pool to reveal a family mystery that turns his life completely upside down. Only Cym and his friends can solve it because, as usual, the grown-ups aren't telling them anything. For the answers you really need, sometimes you have to go deep . . .
