If you love intense thrillers, you'll enjoy the Program by Gregg Hurwitz. Tim Rackley have been recruited by Will Henning to extradite his step-daughter Leah from a cult, once he gets his badge back from the US Marshals. With no information to go on, he looks for clues, past cult members, and members, to get his ticket in. Under a new persona, he goes to the Program, a mind-control colloquium, when he sees Leah. From there, he finds his way to talk to her and to get her out, while now winds up with a special VIP ticket. From there, he convinces Leah proof of what the Teacher does, and finds a way out, after he does an intervention. From there, things go awry, when his cover is blown, and she's in danger. In the end, he brings it all down and Leah safe. What an enjoyable thrill ride.