A bird was once left behind by its owner, trapped in its cage, in a city that had been evacuated due to a volcano erupting nearby. The Twelfth Doctor risked his life in the crumbling city to rescue the bird, whom he then brought to the peak of a mountain; there, in the presence of a delighted Bill Potts (who philosophised that "he always looked out for everyone, no matter who"), he set the bird free and it took flight. (WC: A Hero like the Doctor)