In the second of the Security Breach series, Det. Randall McClellan is still trying resolve who was behind the explosion at Cranesbrook -- and what experiments they were conducting -- when Echo Sloane, the sister of the missing prime suspect, comes to him for help. Randall believes Brayden Sloane is responsible for the loss of his partner and another police officer, and Echo is determined to find her brother. But when her infant daughter is kidnapped, she and Randall battle a new enemy, capable of amplifying human emotions to the point of helplessness. In Critical Exposure (4), Ann Voss Peterson creates a terrifying and complicated thriller.