Expert System's Champion Brother, 2

In Adrian Tchaikovsky's The Expert System's Champion, sometimes the ones you hate are the only ones that can save you. It's been ten years since Handry was wrenched away from his family and friends, forced to wander a world he no longer understood. But with the help of the Ancients, he has cobbled together a life, of sorts, for himself and his fellow outcasts. Wandering from village to village, welcoming the folk that the townships abandon, fighting the monsters the villagers cannot - or dare not - his ever-growing band of misfits has become the stuff of legend, a story told by parents to keep unruly children in line. But there is something new and dangerous in the world, and the beasts of the land are acting against their nature, destroying the towns they once left in peace. And for the first time in memory, the Ancients have no wisdom to offer...