The Sentry by Robert Crais

Joe Pike meets Dru Rayne when he assists her uncle, Wilson, who's been badly beaten by two guys in his restaurant. Enchanted by her, Pike feels the need to keep Dru and Wilson safe. When they go missing, Pike decides he must find out what happened to them. With the help of his best friend, private detective Elvis Cole, Pike discovers that Dru and Wilson are not who they appear to be, but, as usual with Pike, he's all in to find out what's really going on. While The Sentry is a page turner, it lacks the good story with increasing momentum that Crais' most recent novels have (The First Rule, Chasing Darkness, and The Watchman) and you really don't have any sympathy for Dru and Wilson after awhile.