The Doctor remembers Dulkis from a previous visit as a civilised and peaceful place. But times have changed, and his second trip is not quite the holiday he was expecting. The Dulcians themselves are more reluctant than ever before to engage in acts of violence. The so-called Island of Death, once used as an atomic test site, has served as a dire warning of the horrifying consequences of warfare. But an alien race prepares to take advantage of their pacifism…