Warning: Spoilers ahead for Doctor Who season 15, episode 3, "The Well."Doctor Who season 15, episode 3, "The Well," brings back the same monster from 2008's "Midnight," revisiting the lore surrounding the villain and deepening everyone's understanding of it. However, 2025's surprise sequel to the David Tennant episode reveals the faceless entity has changed a lot by the time Ncuti Gatwa's Fifteenth Doctor stumbles into the reunion. Just as Ten was operating on educated guesses, Fifteen doesn't have much else to work with in "The Well" other than centuries-old memories of a solution he never quite found to the threat posed by the enigmatic creature.