Shelter — Harlan Coben

After witnessing his father's death and sending his mom to rehab, Mickey Bolitar has to live with his estranged uncle Myron, and switch to a new school. The one saving grace is Ashley, Mickey's new girlfriend. But then Ashley vanishes without a trace. Unwilling to let another person walk out of his life, Mickey follows Ashley's trail to a seedy underworld that reveals that Ashley wasn't really who he thought at all. And neither, it turns out, was Mickey's father. Soon, Mickey finds himself caught up in a conspiracy so shocking that it makes everything else in his life look like child's play...