Ghost Hold by Ripley Patton

Olivia Black is back.

Only this time she's not the one in need of rescue.

Samantha James, rich, popular, and an award-winning composer at age seventeen, is the next target on the CAMFers' list. In order to convince Samantha to come with them, Olivia and Passion must pose as cousins, blend into the most affluent high school in Indianapolis, and infiltrate a mysterious cult known as The Hold.

Olivia doesn't expect it to be easy, even with the PSS guys backing them up. But what she discovers over the course of the mission will call into question everything she ever believed about herself, her family, and especially about Marcus, the guy she is undoubtedly falling in love with.