Shay, one of the rare survivors of a deadly epidemic called the Aberdeen flu, has surrendered herself to the authorities. She thinks she's a carrier. Along with other survivors, she is sent off to become an unwilling test subject in an effort to find a cure. She's shocked to encounter the mysterious Dr. Alex Cross at the treatment facility. He's her father, though he doesn't know it- is it coincidence that he's one of the immune and involved in the testing?
Meanwhile, a heartbroken Kai is determined to find Shay. He learns that survivors aren't carriers, and that his girlfriend has sacrificed herself for nothing. As the Aberdeen flu spreads across England, Kai teams up with a survivor, Freja, who takes a particular interest in him. They set out to rescue Shay before it's too late. Ghostly Callie, Kai's little sister and the true carrier of the epidemic, will help. But Callie has secrets- especially her plan for the man who murdered her. They've survived the epidemic.... Can they survive the lies?