The snowman - Jo Nesbo

Oslo in November. The first snow of the season has fallen. A boy named Jonas wakes in the night to find his mother gone. Out his window, in the cold moonlight, he sees the snowman that inexplicably appeared in the yard earlier in the day. Around its neck is his mother's pink scarf. Hole suspects a link between a menacing letter he's received and the disappearance of Jonas's mother - and of perhaps a dozen other women, all of whom went missing on the day of a first snowfall. As his investigation deepens, something else emerges: he is becoming a pawn in an increasingly terrifying game whose rules are devised - and constantly revised - by the killer.