After the shocking revelations of the first season, "12 Monkeys" returns for a second season as time traveler Cole continues his decades-spanning journey to prevent a deadly plague from wiping out all of mankind. Due to an unforeseen paradox, Cole finds himself unable to travel back in time. Meanwhile, Jennifer appears to be on the brink of unleashing the deadly virus. Every action has history-altering potential in this mind-bending race against time.