In "Dalek" (2005) a dying Dalek's casing is touched by Rose Tyler, a companion of the Doctor. During this brief physical contact the Dalek absorbs enough of her DNA to regenerate itself and its damaged travel machine. It later becomes apparent that this genetic material has caused it to mutate further, as it begins to experience human emotions. It finally becomes trapped in an agony of conflict and self-loathing, and destroys itself.
