A long-awaited payoff is a powerful thing when it's done right — and occasionally, even when it's kind of wrong. Tonight's bloody, chilling episode of Homeland still falls short of TV's other top dramas by various measures of plausibility. Some plot elements in tonight's episode pop up out of nowhere, and the more wrenching moments of "Still Positive" lack sufficient backstory to justify the tragedy Homeland is clearly trying to evoke. In many ways, the episode is fundamentally flawed in the way the show has always been flawed.

But confidence and energy can get you a lot of rope, and with tonight's strong episode, Homeland has finally regained momentum in its uneven third season.

"Still Positive" is a heart-pounder. All its pieces come together and drive the narrative forward. Even the Dana tidbits are tolerable. The first half of the season has been lackluster and plodding, but "Still Positive" ups the stakes and creates the tension and atmosphere that a show like Homeland requires.

Crucially, Majid Javadi — the third season's long-awaited archvillain — comes off as a genuinely scary guy. Until now, Homeland has done a mediocre job selling the threat posed by Javadi, an Iranian terrorist better known as "The Magician." Sure, we've heard CIA agents call him the mastermind behind the Langley bombing that killed scores of U.S. intelligence officials, but other than that high-profile attack, he's remained largely behind the scenes. We know Javadi befriended Saul years ago; that he embezzles money through Venezuela; and that he wants to meet with Carrie Mathison in an attempt to learn CIA secrets.

All of this was expected — but in "Still Positive," Javadi proves himself sinister and calculating in a graphically ruthless way. The episode ends in blood. There's blood all over Javadi, on Saul's fist, on the floor of a suburban living room. The episode moves fast — clumsily at times, but with a confident energy that sells its crazier twists. Last week's episode ended with Carrie finally meeting Javadi, the long-awaited success of this season's polarizing plot twist. This week's opening is equally tense, as Javadi sets Carrie up with a lie detector and questions her about how she can help him. (Carrie, recall, has been faking mental instability in coordination with interim CIA director Saul Berenson, who is faking the CIA's persecution of her.)

What's extraordinary is how quickly their carefully orchestrated deception falls apart. When it does, Carrie accuses Javadi of embezzlement and tries to arrange a way to bring him in to meet Saul. "Brava, Ms. Mathison," Javadi muses as they stroll alone. "Quite excellent. So when did you and Saul hatch this plan?"

Good question. Carrie cites the 12/12 Langley bombing and says planning started in the early hours of 12/13 — an answer, unfortunately, that creates more than a few plot holes in the season's trickery. If Carrie and Saul have been planning since 12/13, then why, episodes earlier, did Carrie look so brokenhearted when Saul threw her under the bus in front of the Senate Intelligence Committee? She was alone! You can drop the act, Carrie, you know what's really going on here.

But Homeland smartly draws out another thread that it's only hinted at until now: The psychological warfare between Saul and Javadi, with new history inserted to really give "Still Positive" its punch. Saul describes Javadi's transformation from friend to pitiless animal as Javadi, decades ago, killed several people Saul was trying to protect. He calls Javadi a "stubborn man" and worries the CIA won't be able to turn him, at least not easily. Saul's one consolation after those past murders was helping Javadi's wife and daughter escape to the West, he tells Fara.

And now he's back, and worse than ever. Javadi, who's on to Carrie and Saul's plot, decides this is the perfect moment to reunite with aforementioned daughter and ex-wife, as Carrie and Quinn rush to catch up with him. He shoots his now-grown daughter in the head mere feet from his infant granddaughter and then stabs his ex-wife to death with the shards of a bottle. "Now I'm ready to see Saul," Javadi declares amid what Quinn calls "a fucking bloodbath" of domesticity, the baby crying in the background.

Once Javadi is in Saul's custody, Saul finally loses it. He tells Carrie and Quinn to unchain Javadi, only to harshly punch his former friend in the face. Cue credits.

It's a powerful, cutting moment given the brutal depression Saul faces. Awkwardness and grief surround his own marital situation, and as "Still Positive" begins, he clearly has given up on any claim to his wife. He has lost control of the agency that will no longer be his in a matter of weeks. "God, Saul, stop this detached routine," his wife tells him early on. "Just get angry at something. Get angry at me."

As it turns out, Saul prefers getting angry at Javadi. Although Javadi murdering his former family just to punish Saul may seem like a manufactured plot development — a development that hinges on characters we didn't know existed until 20 minutes before their deaths — the execution is genuinely startling. Javadi has become the outsized villain this season of Homeland has needed — willing to shoot his own daughter in the head to make a point.

The whole episode moves with greater consequence than before. In yet another twist, we learn that Carrie is pregnant. (By Brody, or the random guy she met early this season, or someone else? She apparently hasn't seen Brody in months and isn't showing yet.) A drawer full of past pregnancy tests confirms it, because her life wasn't complicated enough already.

And while we're on the subject, "Still Positive" includes zero Nick Brody, who has appeared in just a single episode this season. When will he return? The smart bet is that Javadi knows exactly where Brody is, and that his whereabouts will become a bargaining chip in Javadi's negotiations with Saul.

It took a little while, but the pieces of Homeland's third season are falling into place, and Homeland finally feels like the drama it once was. Expect the stakes to get even higher in the weeks to come.

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