The fourth year ends with a viral outbreak, followed by the death of a key character. For the most part, though, the conclusion holds out hope for relations between the positives and the rest of the population--if they can stop the Marked in time. Because the USA Network chose not to renew the show, some questions may never be answered. Fortunately, The 4400 went out with both humor and heart. Extra features include deleted scenes, featurettes, a blooper reel, and commentary from creator Scott Peters on "Till We Have Built Jerusalem" and the director's cut of finalé "The Great Leap Forward." --Kathleen C. Fennessy