The Ancestor Cell is a novel by Peter Anghelides and Stephen Cole, based on the science fiction television series Doctor Who.

Following on from the events of The Banquo Legacy, the Time Lords have cracked the base code the Eighth Doctor programmed into Compassion's randomiser, and intercept her at her next destination.

Meanwhile, Fitz appears before a group of disenchanted, young Time Lords who are holding rituals based on the occult texts of Faction Paradox and finds himself unable to escape.

Getting further embroiled in the group's activities, Fitz witnesses the creation of a copy of former President Greyjan the Sane and is then the unwitting donor of material used to pull the original Fitz Kreiner, now in the guise of Faction Agent Father Kreiner, from a Klein bottle universe into the modern day Gallifrey.

During her Reaffirmation Ceremony, Lady President Romana is challenged by Greyjan and placed under house arrest, with only Fitz as company.