Ellen Tigh

Ellen Tigh was the wife of Colonel Saul Tigh, a scientist of the original Earth, and one of the Final Five Cylons. According to Samuel T. Anders, she led the experiments that rediscovered Resurrection technology on the original Earth some two thousand years before the Fall of the Twelve Colonies. On reaching the Cyrannus star system with the other four, she was responsible for creating the humanoid Cylon models that would carry out the Cylon Holocaust, and she regained her full memories when she resurrected after her death on New Caprica. (Battlestar Galactica, "Sometimes a Great Notion"; Battlestar Galactica, "No Exit")

The original Earth#

Ellen was born on the original Earth and built her career as a scientist studying Resurrection, the defunct technology once used by the Thirteenth Tribe to transfer conscious minds into cloned bodies. Two of her group were in contact with the Messengers, who knew the secrets of the technology and had warned of a coming revolt by the tribe's sentient mechanical workforce. The five succeeded in their work and placed a ship in orbit to download their minds at the moment of death. (Battlestar Galactica, "No Exit")

When the holocaust came, the five woke aboard that ship, and with nowhere else to go set a course in search of the Twelve Tribes, warned by the Messengers that those tribes would one day build sentient machines of their own. Lacking faster-than-light drives, they crossed the distance over several thousand years, experiencing little of its passage. (Battlestar Galactica, "No Exit")

Mother of the Cylons#

By the time the five reached the colonies, the Cylon War had already begun. To end it, Ellen offered to build humanoid models for the Cylons and grant them Resurrection. Her first creation, Cavil, whom she modelled on the image of her own father, John, became sadistic and came to believe Ellen favoured a later model, Daniel, over him. Cavil poisoned the genetic code of the Daniel line, effectively ending it, and killed the Final Five. On their resurrection he blocked access to their original memories and placed them among the Twelve Colonies to witness the evils of humanity while believing themselves human. (Battlestar Galactica, "No Exit")

Life as a human#

In her human life, Ellen was married to Saul Tigh, who in the years before the Fall took a post aboard Galactica as executive officer to his friend William Adama. Adama believed the marriage had fed Tigh's drinking and disliked it, and during Saul's absences Ellen had a number of affairs within the fleet. When the Cylons occupied New Caprica, she collaborated with them to save her husband, and Saul poisoned her when he discovered what she had done. (Battlestar Galactica, "Tigh Me Up, Tigh Me Down"; Battlestar Galactica, "Occupation"; Battlestar Galactica, "Exodus, Part II")

Resurrection#

Ellen resurrected aboard a Cylon ship, where Cavil held her prisoner; by downloading into a new body she regained the memories Cavil had blocked, and the wisdom of many lifetimes at first lent her a greater magnanimity. After the Resurrection Hub was destroyed, Cavil sought her knowledge of the technology, but without the other four she could not provide it, and she rebuked his claim that the bodies she had designed were imperfect. Against his contempt for human traits, she argued that humans possessed something real and precious: love, compassion, creativity and emotion. She told him she still loved him because she had created him, and that the events since the Fall had been orchestrated by the one true god. Cavil resolved to kill her and extract her knowledge from her brain, but she escaped with the help of Sharon "Boomer" Valerii. (Battlestar Galactica, "No Exit")

Return and reconciliation#

Back among humans aboard Galactica, Ellen proved still fallible. Her jealousy over her husband's bond with Adama led her to cast a deadlock-breaking vote in favour of the rebel Cylons and the Final Five leaving the human fleet, which forced Saul to declare he would stay regardless and caused Caprica Six to doubt his love, contributing to the miscarriage of Saul and Six's unborn child. Though at first furious to learn of Six's pregnancy, having herself never been able to bear children, Ellen came to regret the consequences of her manipulation and admitted she had not truly wished to leave Galactica. (Battlestar Galactica, "Deadlock")

It later emerged that Cavil had orchestrated Ellen's escape so that Boomer could abduct the hybrid child Hera. Ellen volunteered the Final Five for the mission to rescue the child from the Colony, and during the battle she, Tory Foster and Galen Tyrol tended to Anders as he served as Galactica's Hybrid. She was shocked to learn that Foster had murdered Cally, and she and Saul did not hold it against Tyrol when he killed Foster in revenge. In the end she and Saul rekindled their bond and resolved to spend the rest of their lives together on humanity's new homeworld. (Battlestar Galactica, "Someone to Watch Over Me"; Battlestar Galactica, "Islanded in a Stream of Stars"; Battlestar Galactica, "Daybreak, Part II")