A brilliantly imagined new 8+ adventure about resilience, family and hope. From the bestselling and Waterstones Children’s Book Prize shortlisted author of BOY IN THE TOWER. Perfect for fans of Ross Welford and Lisa Thompson.

Even when you can’t believe what you’re seeing, you’d better get ready to run for your life, because the Greys have come to town. Billy’s mum isn’t like other mums. He calls her Sylvie, they move house every few months and she spends all their time together teaching him The Rules of Survival – how to make fire, build shelter and find food.

Following the Rules is the only thing Sylvie asks of Billy and the tests get more extreme, until one day she goes too far . . .

Whilst Sylvie is getting better, Billy has to live with the dad he’s barely met. At Dad’s, Billy misses his mum and keeps practicing the Rules, but he also learns new things, like how it feels to make a friend and be part of a different type of family. And then the world changes for ever.

People are being infected with a mysterious virus that turns their skin grey. Chaos breaks out and Billy and his family flee the city. Their journey is the ultimate test of survival and Billy knows that this was what Sylvie was preparing him for.

She knew what was coming. But once he has gotten his family to safety, Billy still has to find Sylvie and tell her what he’s discovered about the ‘Greys’ – not just to save his family, but the whole world.