The Falls by Ian Rankin
A student has gone missing in Edinburgh - completely out of character. She's not just any student, though, but the daughter of extremely well-to-do and influential bankers. There's almost nothing to go on until Detective Inspector John Rebus gets an unmistakable gut feeling that there's more to this than just another runaway spaced out on unaccustomed freedom or worse. Two leads emerge: a carved wooden doll in a toy coffin, found in the student's home village, and an Internet role-playing game. The ancient and the modern, brought together by uncomfortable circumstance and a curmudgeonly detective happier with long playing records than digital technology ...In this powerful novel, Rankin, who 'moves dialogue with the precision of a chess-master', (Irish Times) brings together past, present and future in a terrifying duel of good - in the persons of DI Rebus and DC Siobhan Clarke - and evil.