Sean McFarland is AOD's most dangerous Omega operative—beautiful, lethal, and impossible to control. Except, perhaps, by Michael Truman. Michael is the head of AOD operations, the man who trained Sean into a weapon and knows exactly how to stop him when no one else can. But when a forged transfer order exposes the buried remains of the Override program, Sean begins to realize that his abilities, his instability, and even the forces shaping his bond with Michael may be connected to an experiment that never truly ended. Then another Override subject, OVR-04, is brought back into AOD custody. As years of suppressed desire between Sean and Michael finally cross the line, Four begins showing impossible reactions to Sean. Michael once believed that if he understood Sean's missions, biology, weaknesses, and every trigger, he could control him. But Sean has never been asking whether Michael can control him. He wants to know something far more dangerous: If Sean is completely free to choose, will Michael still choose him?