Adrian admits that the only “loose thread” he had to deal with was the violent investigation being conducted by Rorschach, but he found his way to neutralizing the mask-wearing detective by tipping the cops that he was going to be at Moloch’s place – which had the desired effect of landing Rorschach in prison (at least temporarily).
Moving on to the main event, and continuing to effortlessly stop continued attacks from his former friends, Ozymandias finally tells Nite Owl and Rorschach about his endgame – which is detonating devices in key regions around the globe with the intention of killing 15 million people. Thanks to the tachyon technology employed, the world would believe that the attacks were initiated by Dr. Manhattan to punish humanity for letting the Doomsday Clock get so close to midnight. Rorschach says that he and his crime-fighting partner won’t let it happen, but then Adrian explains,
Article source: https://www.cinemablend.com/news/2553084/watchmen-ending-explained-how-its-significantly-different-from-the-end-of-the-comic