For a three-act plot analysis, put on your screenwriter’s hat. Moviemakers know the formula well: at the end of Act One, the main character is drawn in completely to a conflict. During Act Two, she is farthest away from her goals. At the end of Act Three, the story is resolved.
Act I (Chapters I - III)
Rorschach lives on canned beans and vengeance, so he’s hungry to solve the Comedian’s murder. No can do, as long as he works solo. Even after Dr. Manhattan ditches Earth for Mars, Rorschach can’t convince Nite Owl to come out of retirement.
Act II (Chapters IV —IX)
An assassin tries and fails to kill Veidt, who’s got the reflexes of an over-caffeinated squirrel. Rorshach is framed for a murder he didn’t commit, and gets sent upriver to Sing-Sing (prison). This leads to Nite Owl and Silk Spectre breaking him out. After the dust settles, Silk Spectre brings Dr. Manhattan back down to Earth.
Act III (Chapters X —XII)
Nite Owl and Rorschach discover Veidt is Dr. Evil. New York City is blown to bits. Before leaving the galaxy, Dr. Manhattan kills Rorschach to preserve world peace. Nite Owl and Silk Spectre get married. Thanks to an ambiguous ending, the future is totally unknown.