Dallas’ third season has been a wild one — arson, murder and sexual seizures are now commonplace at Southfork — but star Josh Henderson assures TVLine that Monday’s killer two-part finale (TNT, 9/8c) is “the biggest episode we’ve done yet.”

RELATED Dallas Finale Recap: Fall in the Family

“We won’t all make it out alive,” Henderson says, confirming that TNT is making good on its nerve-wracking “One. Ewing. Will. Die.” promo mantra. “For the first time, nearly every character is in danger all at once. The stakes have never been higher.”

In fact, John Ross will be throwing himself directly in the line of fire, as the entire family rallies to save Ann and Emma from the cartel.

“He makes a big decision in the finale, a dangerous one, because he wants to do right,” Henderson says. “He wants to right his wrongs and make a big move, and that’s exactly what he does in the finale.”

But is it too little too late, or can J.R.’s son actually piece together his shattered reputation? (Not to mention his shattered marriage.) For his part, Henderson remains hopeful.

“John Ross really does love Pamela, and he knows he screwed up,” he says. “In the finale, he’s thinking, ‘How can I save my marriage? How can I save my family? How can I be a hero?’ He’s torn, and he’s willing to risk everything to prove his loyalty.”

In addition to a game-changing death, a particularly “intense” scene in Monday’s finale also features the world premiere of “I See You,” an original track written by Henderson.

“I wrote it about John Ross’ storyline, about the ghost of J.R. and how he’s trying to escape him,” Henderson explains. “Everyone says he’s just like his father, and he knows it’s true. I can’t wait for people to see what I’ve been up to on the music side. For me, it’s a really exciting night.”

Dallas fans, which Ewing do you think will die tonight? Browse preview photos, then drop a comment with your best guesses below.