For Gene and the remaining humans - or hepers - death is just a heartbeat away. On the run and hunted by society, they must find a way to survive in The Vast... and avoid the hungry predators tracking them in the dark. But they're not the only things following Gene. He's haunted by the girl he left behind and his burgeoning feelings for Sissy, the human girl at his side.

When they discover a refuge of exiled humans living high in the mountains, Gene and his friends think they're finally safe. Led by a group of intensely secretive elders, the civilisation begins to raise more questions than answers. A strict code of behaviour is the rule, harsh punishments are meted out, young men are nowhere to be found - and Gene begins to wonder if the world they've entered is just as evil as the one they left behind. As life at the refuge grows more perilous, he and Sissy only grow closer. In an increasingly violent world, all they have is each other . . . if they can only stay alive.