Alien sleeper cells on Earth are awakened when invaders threaten the planet. For thousands of years, Sentinels have walked among us, awaiting the moment they would be called into action. Josie's boyfriend, Bane, is a Sentinel. Being one of the cells, Bane becomes a cold-hearted, single-focused machine bent on ensuring humanity's survival. Josie barely recognizes the man she once knew and loved with all her heart. Though Bane is determined to protect Josie and secure the small town they escape to, Josie cannot help but look upon him with trepidation and suspicion. She wonders if Bane is really intent on keeping her and the others alive or if he is actually the real threat they face.