"Who shot J.R.?" Those were the words on the lips of Dallas fans throughout the world as the popular prime-time serial launched its fourth season on CBS. Speculation ran high over the identity of the person who, at the tail end of season three, had pumped several slugs in the chest of the sublimely unprincipled Texas oil tycoon J.R. Ewing (Larry Hagman). It was one of the best-kept secrets in the annals of popular entertainment; indeed, not even the cast members knew "who dun it" (to cover their bets, the producers filmed scenes of every member of the cast pulling the trigger -- including Larry Hagman). During the fifth episode of the season, which became the second highest-rated show in TV history, the culprit is exposed -- and it is giving nothing away at this late date to reveal that J.R.'s would-be assassin was his cast-off mistress Kristin (Mary Crosby), younger sister of his own wife, Sue Ellen (Linda Gary). Upon his recovery, J.R. resumes his power struggle with younger brother Bobby (Patrick Duffy), who in J.R.'s absence has assumed control of Ewing Oil. Almost immediately upon returning to his office, J.R. hires sharkish PR agent Leslie Stewart (Susan Flannery) to promote his "new" image as "The All-American Businessman" -- even as he tries to undermine his own country's foreign affairs by engineering a political coup in a faraway country in order to increase his wealth!
Meanwhile, Sue Ellen's lover, Dusty Farlow (Jared Martin), urges her to leave J.R. and take her son, John Ross (now played by Tyler Banks) with her. After numerous dead-end love affairs, J.R.'s niece Lucy (Charlene Tilton) decides to marry Mitch Cooper (Leigh McCloskey), a poor medical student who is troubled by the Ewing's affluence; J.R. doesn't think much of Mitch, but he develops a hankerin' for his sister, Afton (Audrey Landers), a professional singer. And in one of the season's most momentous developments, Southfork manager Ray Krebbs (Steve Kanaly) is revealed to be the illegitimate song of J.R. and Bobby's dad, Jock Ewing (Jim Davis) -- whereupon Ray further increases his influence in the community by wedding the politically powerful Donna Culver (Susan Howard). In an effort to whip up audience interest in the same manner as the previous season's cliffhanger, season four of Dallas closes as attorney Cliff Barnes (Ken Kercheval), sworn enemy of J.R. Ewing, finds the body of a woman floating in the Ewings' swimming pool. Even if this contrivance hadn't occurred, CBS had no fear that Dallas would lose its audience; as of the end of its fourth season, the series was America's top-rated series -- the first dramatic program to pull off this coup since Marcus Welby, M.D.