Watchmen takes place in an alternate history United States where the country is edging closer to a nuclear war with the Soviet Union, freelance costumed vigilantes have been outlawed and most costumed superheroes are in retirement or working for the government. The story focuses on the personal development and struggles of the protagonists as an investigation into the murder of a government sponsored superhero pulls them out of retirement and eventually leads them to confront a plot by one of their own to stave off nuclear war by killing millions of innocent people.