The Boy Who Swam with Piranhas — David Almond

Stanley Potts's uncle Ernie has developed an over-the-top fascination with canning fish in the house, and life at 69 Fish Quay Lane has turned barmy. But there's darkness in the madness, and when Uncle Ernie's obsession takes an unexpectedly cruel turn, Stan has no choice but to leave. As he journeys away from the life he's always known, he mingles with a carnival full of eccentric characters and meets the legendary Pancho Pirelli, the man who swims in a tank full of perilous piranhas. Will Stan be bold enough to dive in the churning waters himself and choose his own destiny?