The season two premiere begins three months after Tom Mason agreed to go with the alien invaders. Weaver is still in command of the 2nd Mass, while Anne continues to serve as medic. They have seen many battles and are a much leaner unit now. Pope has taken command of the Berserkers, a renegade group within the 2nd Mass that Weaver doesn't fully trust. When Tom suddenly returns, he is faced with doubt about his loyalties to the group. Meanwhile, Hal and Ben continue to drift apart as Ben challenges his older brother's authority.