Stormbringer l: The Rat and the Raven

Ten years after a terrible accident that stripped the earth with laser burns seven kilometres wide and brought an end to most of human civilisation, patches of settlement still survive. One is the University, which maintains a population and a structure and now has time and resources to find out what happened to some of its students, sold as slaves, while the University was ruled by a despot. Bran assembles a group, including a very cautious thief, twin girls and the strong man Mill the Hill, as well as Swart, a brother of one of the lost slaves.
They set out for their first mission by train, for a place now called The Rat's Town, where Bran meets a transmitting empath called Scathe, who joins the group as they go further; first to find the lightning maker, the Stormbringer and then, further still, to return to find that their minds are not their own, and that their very worst nightmares are becoming very real indeed.