Exodus, Part Ⅰ is an episode of the TV series, Battlestar Galactica, and aired during the show's third season.
At the end of the previous episode "Precipice", 200 humans are facing a Cylon Centurion firing squad. A few hours prior, Galen Tyrol (Aaron Douglas) receives the list from a source, and gathers a group of armed resistance members to the execution site and are able to destroy the Centurions before the execution takes place. Meanwhile, Sharon Agathon (Grace Park), Samuel Anders (Michael Trucco) and other resistance members are under fire from another group of Centurions, but are rescued by marines Sharon posted. Afterwards, Sharon discusses with the resistance her plan to rescue those on New Caprica from the Cylons; she is to go into the Cylon compound in the city to gather the launch keys for the ships on the ground while Galactica will distract the Cylons so the humans could escape. Anders finds the rendezvous map on one of the dead Cylons that Ellen Tigh (Kate Vernon) claimed to have burned. He confronts Saul Tigh (Michael Hogan) about his wife's betrayal. Ellen confesses to her action, but claims to be doing it to keep Tigh alive.
Meanwhile, D'anna Biers (Lucy Lawless) has a nightmare and visits an oracle, who hints that Hera, the Cylon-Human baby who was born and supposedly killed in "Downloaded" is still alive, and D'anna "will know true love" again and hold the child in her arms. Later, Sharon infiltrates the Cylon compound and acquires the launch keys, but is stopped by D'anna, who recognizes her immediately, and tells her Hera is still alive. However, Sharon refuses to believe it. To prevent D'anna from warning the Cylons, Sharon incapacitates her by knee-capping her. Having heard the launch keys have been retrieved, Admiral William Adama (Edward James Olmos) starts preparation for battle. He instructs his son Lee "Apollo" Adama (Jamie Bamber) to wait for 18 hours. Should Adama fail to arrive in time, Apollo should lead the remainder of the fleet to Earth.