Three years of wandering the post-apocalyptic wasteland has stripped Dr. Chris Welsh of hope. A harrowing loss drove him from his home and he hasn't stopped moving - until he encounters Valle de Bravo, a haven of civilisation amid the chaos of the Change. Soldiers take their orders from Rosa Cortez - the iron hand within a velvet glove. The last thing Rosa needs is a feral loner upsetting the town's tentative balance.