TNT’s revival of “Dallas” resumes at 9 tonight with a two-hour season premiere that’s bittersweet knowing that the show’s most valuable player, J.R. Ewing, will soon be gone. Actor Larry Hagman, who became inextricably linked with J.R., died in November, and his character will be killed off a few episodes into the new season.

Executive producer Cynthia Cidre, who developed the new “Dallas,” has done her best to introduce new characters and stories, but J.R. remains the heart of the show and always gets the best lines.

“I came over to deliver some muffins to the pretty little secretaries,” J.R. says during a visit to the new Ewing Energy offices in tonight’s premiere. “Who could guess so many would turn out to be men? Where’s the sport in that?”

At the end of the first season last summer, viewers learned, in a surprising, satisfying twist, that Christopher Ewing (Jesse Metcalfe) had been tricked into marrying the daughter of Ewing nemesis Cliff Barnes (Ken Kercheval). It turned out Rebecca Sutter (Julie Gonzalo) was actually Pamela Rebecca Barnes, daughter of Cliff and Afton.

The early part of the new season finds Christopher trying to get the marriage annulled while his cousin, John Ross (Josh Henderson), does his level best to undermine those efforts for his own selfish gain.

It remains to be seen how “Dallas” will cope with the loss of its finest player. Some reports suggest J.R. will be murdered around Episode 7, and “Dallas” will spend the remainder of its 15-episode second season playing out “Who killed J.R.?,” aping the old “Who shot J.R.?” plot that gave the show its buzz back in the 1980s. If that’s the direction “Dallas” heads, it’s a smart move, a way to build buzz using nostalgia as the basis for a new mystery.

Tonight’s premiere introduces Judith Light (“Ugly Betty”) as a new Ewing nemesis. She’s caught up in a story involving Bobby’s current wife, Anne (Brenda Strong).

And Sue Ellen (Linda Gray) gets her heart broken and threatens to lapse back into the alcohol addiction that plagued her through the first run of “Dallas.” She gets support from a perhaps unlikely source, ex-husband J.R., in a scene that would seem to give some closure to that relationship before J.R.’s demise.

“If I can throw my weight around this town after all the crap I’ve pulled,” he tells her, “you’ll bounce back just fine.”

No question about it: “Dallas” may or may not be able to bounce back, but it won’t be the same once J.R. Ewing is in the grave.