Nurse (World Enough and Time)

The nurse was a Mondasian and a descendant of the original skeleton crew of a Mondasian colony ship caught in the gravitational pull of a black hole. Because of the black hole's time dilation, the bottom of the ship had a much faster flow of time than the top of the ship.

The nurse was the surgeon's assistant. At some point they established Operation Exodus. It involved augmenting hospital patients by turning them into Cybermen so that they would survive the journey to the top of the ship. However, the process was extremely painful and to keep its nature a secret, the nurse would typically silence any patients who cried out in pain.

She eventually met Bill Potts who was in Mr Razor's care and treated her condescendingly, always making her do the cleaning around the hospital and forbidding her from going outside.

The nurse was present when Bill was tricked by Razor into entering the conversion theatre and was transformed into the first fully successful Mondasian Cyberman. (TV: World Enough and Time)