An alien race holds the ownership human race by convincing they have helped humans since the dawn of time and that they are the sworn protectors of earth. Bill, convinced that this is not the truth, with the help of Nardole track down The Doctor - that apparently is making advertising for this new alien race to help them keep their power - to help the cause of freeing the earth of this parasite no matter how harsh are the consequences to achieve it. Is the Doctor on the human or the alien band and can they free themselves from this dictatorship they impose?
—Jose Benavides