内容简介：
Beth Sims has just committed a murder. After her boyfriend brutally attacks Beth and her daughter, she leaves the rain of Seattle for the heat of Arizona to attend The Oasis, a self-defense spa. After being observed by the owners, Beth is shocked to learn the true intent of the spa and that she's been hand picked to join the inner circle of retribution-"The Exchange," The Oasis is a cleverly disguised machine, training a select few who have been failed by our justice system, to become assassins. Using the old adage of criss-cross, Beth murders someone she's never met in exchange for ridding herself of the man who violently attacked, stalked, and threatened her and her young daughter.