The Falls - softcover - Ian Rankin

A student has gone missing in Edinburgh and there’s very little for Detective Inspector John Rebus to go on apart from his gut feeling that there’s more to this case than a runaway high on unaccustomed freedom.
Two leads emerge: a carved wooden doll in a tiny coffin and an Internet role playing game. Rebus concentrates on the coffin, eerily reminiscent of sixteen similar relics found on a hillside in 1836, leaving DC Siobhan Clarke to deal with the cyberspace Quizmaster. She’s young enough to navigate the net, but she may not have the experience to spot the pitfalls in a game where lives depend on split second timing. With Rebus buried two hundred years in the past, DC Clarke is going to need more than just luck to save both their skins — professional and personal