Nicholas Brody is back, and he is not looking good. Bald, bloodied, and dirty, the former war hero may not be cut out for life as an international fugitive.

At the end of Homeland's second season, Brody fled to Canada after his terroristic leanings were made public and he was (seemingly) framed for killing hundreds of Americans in the 12/12 Langley bombing. This third episode of season three, "Tower of David," reintroduces us to the gravelly voiced veteran — and boy, does it make sure he suffers. In the first scene, Brody is shot twice in the stomach by Colombians. In the last scene, he ends up in a cell in Venezuela in a bizarre, half-constructed building — the titular Tower of David.

With Brody back in the mix, "Tower of David" serves as a generally unpleasant exercise in hammering home just how far the show's two lead characters have fallen. Structurally, "Tower of David" is an unusual episode of Homeland. In a decision that will likely come as a relief to some fans and disappoint others, the episode zeroes in on just Brody and Carrie at the expense of the show's other characters: Neither the Brody family nor Saul, who have figured so heavily in the first two episodes, make an appearance.

But "Tower of David" does return to the agonies of Carrie Mathison, now committed in a mental institution for three weeks and back on lithium. The former lovers both face their share of suffering, Carrie's mental and emotional and Brody's often devastatingly physical. It's not an easy hour of TV, and its heaviness and lack of broader narrative momentum makes it feel even longer. The problem is that it's unclear whether this suffering will lead to any actual growth for Carrie and Brody. Both characters have endured so much already that they seem numb to the damage constantly inflicted on them by their surroundings and their own choices.

It also raises some questions about Homeland, which went far out of its way to hide what happened to Brody until "Tower of David." Teasers for the show attempted to play up that mystery, ramping up even more expectations. But after all that buildup, the bald, wounded creature we meet here — and the extended sequences of confusion and listlessness he appears in — fail to really elevate the narrative.

But even if "Tower of David" is largely spent on desperation and tears, it does leave some intriguing questions unanswered: What exactly is that Tower of David, and who are its trapped inhabitants? "We're here because the world outside can be judgmental and cruel," a bemused doctor tells Brody. "We're here because this is the place that accepts us." The doorless skyscraper includes children, a pretty young woman named Esme, and several thuggish men ready to kill. One spider-tattooed leader knows the millions of dollars he could get for delivering Brody back to the United States — but he also name-checks Carrie Mathison, and seems unready to collect the reward for his prisoner.

Back in the United States, the latest wrinkle in Carrie's story is her recurring psych ward visitor. Nope, it's not Saul, as Carrie hopes, but Paul, a suave attorney. He promises to be a partner who is invested in Carrie and believes in her sanity. They want to get her out of the hospital, he says, but Carrie — apparently correctly — accuses him of being a foreign agent looking to turn her against the CIA. The rest of her scenes are shaky lithium daydreams. She asks a doctor to tell Saul how well she's doing and praises the choice to return to medication … but in other scenes, she's slamming her head against a bathroom mirror like she's possessed by BOB. Carrie is far from okay.

The episode's circumstances are a reminder of how lonely these characters' lives really are, and why Carrie and Brody were drawn to each other in the first place. Neither had deep connections with those who understood them, and both were isolated by the traumas of their past. Brody was scarred from torture, and from playacting the life of a patriotic American for the bulk of the past two seasons. Carrie, meanwhile, was playacting enough stability to make the CIA trust her judgment. When Homeland operates as a thriller, with a broader direction and bigger stakes to the plot, this personal emptiness is less apparent. The characters are just too busy.

But here, the underlying blankness of Carrie and Brody comes out. Carrie's biggest accomplishment these days is building a little popsicle-stick fortress. Brody is on the run, with no real destination while the international manhunt persists. The doctor offers some wry analysis near the episode's end. "You're the cockroach," he tells the bloodied Brody, "still there after the last bombs go off."

He's right. Carrie and Brody are survivors, but their survival has come at a heavy cost. Carrie doesn't have Saul or even Brody. And Brody has even less. "I just need to get to the next place," he insists in one key scene. But there's nowhere left for him to go.

Read more Homeland recaps: