They call it the Sickness. Nobody knows what causes it or where it comes from. Nobody knows why it only seems to affect the adult population. But everyone knows that if you catch it and you're over 18, you die.

All around the world, teenagers like Travis, Richie, Mel, Jessica and Simon, find themselves thrown together and forced to cooperate. But a world without rules is not the utopia many survivors thought it would be. Everything, now, is deadly serious. Those who can't adjust to their new situation find themselves going the same way as the adults. Factions form quickly. Some want to take what they need through strength of arms, but others - the most organised - want to try to rebuild the world their parents left behind. Restoring society will be hard, but not impossible. After all, they reason, the worst is over.

But they're wrong. It's only just begun. . .