As Rorschach digs deeper, he discovers a conspiracy involving a group of costumed vigilantes known as the Minutemen, who were active in the 1940s and 1950s. He also learns about a substance called "Prometheus", which has the power to give people superpowers.
Rorschach teams up with Nite Owl, a former superhero who is now retired, and Dr. Manhattan, a powerful and god-like being who was created by Veidt. Together, they confront Veidt and discover that he is the mastermind behind the conspiracy. Veidt's plan is to use Prometheus to destroy a major city, thereby uniting the world in fear and preventing nuclear war.
Rorschach, Nite Owl, and Dr. Manhattan try to stop Veidt, but they are too late. Veidt detonates the bomb, destroying New York City and killing millions of people. The aftermath of the disaster leaves the world in chaos and uncertainty.
The Watchmen is a complex and morally ambiguous story that explores themes of heroism, vigilantism, and the nature of good and evil. It is also a commentary on the Cold War and the threat of nuclear war.