Season 1 picks up where the miniseries left off. After engaging in a losing battle against the Cylons, humanity's last remnants are forced to flee under the protection of their one remaining warship, the outdated Battlestar Galactica. Pursued by the Cylons-some of whom have now taken human form-Commander Adama and President Roslin lead these last remnants of humanity in search of a new home - a planet called Earth.

Picking up where the first season left off, season 2 continues to chronicle the adventures of a ragtag fleet of humans, the sole survivors of a devastating nuclear attack by the robot Cylons. But it soon becomes clear that more threatens this fragile society than external forces. Massive fear, paranoia, and political ambition — all classic plagues to developing civilizations — wear away at the already-fatigued fleet.

Season 3 picks up where last season's cliffhanger finale left off, the Galactica crew discovers a habitable planet, but things become even further complicated when the Cylons, led by Caprica Six and Sharon, find the planet and offer humanity a stunning proposal of peace.

As season 4 begins, the last remnants of humanity continue their search for a new home. Galactica’s crew attempts to make sense of the inexplicable while four members of the fleet are still reeling from past revelations.