Eighteen-year-old elite swimmer Cherry Morgan is offered a legal, medically supervised biotechnology that might improve her performance by just one per cent.

One per cent sounds small. In elite competition, it can separate qualification from elimination, opportunity from disappointment, and an ordinary result from a life-changing one.

As opportunity, friendship and ambition collide, Cherry must decide what she is prepared to accept in pursuit of an advantage — while the people around her confront their own ideas about fairness, technology and success.