This post discusses the plot of the Dec. 7 episode of “Homeland.”

As Dennis (Mark Moses) and Martha Boyd (Laila Robins) were herded into the embassy’s panic room along with CIA Director Andrew Lockhart (Tracy Letts) toward the beginning of “13 Hours in Islamabad,” I found myself wishing for something unexpected: that “Homeland” would do a bottle episode. In previous seasons, the thought of spending a whole hour of television in a single room with the show’s characters — particularly if those characters were going to be Carrie Mathison (Claire Danes) and Sgt. Nicholas Brody (Damian Lewis) — might have been unbearable.

But “Homeland” has done an excellent job this season of fleshing out its roster of characters, enough so that I wouldn’t have minded slowing down the show’s newly confident action sequences for an episode and just letting the characters talk to one another. Given that Haissam Haqqani (Numan Acar) has invaded the U.S. Embassy, though, I can forgive “13 Hours in Islamabad” a few frenetic firefights and the sight of Peter Quinn (Rupert Friend) off on a revenge mission in exchange for the tense, acting-driven moments “Homeland” decides to grant us.

Among the best parts of the episode were the sequences in which we got a look at who Lockhart really is under pressure. For two seasons now, the wily CIA director, who used congressional hearings to advance his plan to take Saul’s job, has talked a good, tough game.

But under actual fire, he wilts. He doesn’t understand the culture of his own agency enough to comprehend why Sandy Bachman (Corey Stoll) kept a single, physical-copy list of his assets in Pakistan under lock and key in the embassy rather than backing it up digitally at Langley, where it might have been vulnerable to leaks. And when Haqqani and his men march into the room where agents are burning documents and destroying their hard drives, Lockhart cowers against a wall, paralyzed by his first sight of violence. A CIA agent has to tell the director to run, to safeguard the tremendously classified information in his hands. Lockhart is in no position to give orders.

And once Haqqani arrives at the panic room, using the security camera mounted above the door to force the embassy staff to bear witness to his executions of CIA agents, Lockhart reveals himself to be not just prone to panic, but also sentimental. After watching two of his men get shot in the head, Lockhart crumbles when Haqqani holds a knife to Fara’s (Nazanin Boniadi) throat. Maybe it’s because she’s a woman, or maybe it’s because he has been sickened by previous beheading videos, but Lockhart makes the highly emotional decision to give Haqqani what he wants: Bachman’s list of names, all of whom Haqqani will clearly kill, probably in some deeply terrible ways.

“It’s a war,” Martha tells Lockhart, trying to get him to stand his ground, no matter how awful it might be. Lockhart pushes her to the ground and begins begging Haqqani for patience over the intercom. Of course, Haqqani kills Fara anyway. In every way possible, Lockhart has shown himself unfit for the pressure of his job and unable to understand the nature of the conflict that he has had a part in directing. I dearly hope “Homeland” finds a way to deal with his actions, not least as an apology for inflicting Lockhart’s smarm on us for so many episodes, but also because they say a lot about the dangers of technocratic overconfidence.

The other standout part of the episode is a conversation between Dennis and Martha after the attack is over. While the attack was ongoing, Dennis’s treachery was a lower priority than mere survival. But in the grim aftermath, the true cost of Dennis’s pathetic quest to feel important and manly gets toted up, and Martha is justifiably even more disgusted than she was before.

“36 people lost their lives today, Dennis,” she tells him wearily when he summons her to detention. “Why am I here? What do you want?” Martha demands of her husband, convinced they have nothing left to say to each other. “Give me your belt,” Dennis asks her, asking for the opportunity to commit suicide rather than be taken back to the United States. “Think about it, Martha. I could spare you a lot of heartache.” “Yourself, you mean,” Martha tells him bitterly and with great clarity. But ultimately, she gets Dennis’s own belt out of the safe and tosses it on the floor outside Dennis’s cell like so much garbage, in reach of her ruined husband.

“Homeland” has gotten a bit hanging-happy over the past two episodes. So I was pleasantly gratified by the twist here, that Dennis turns out not to have the fortitude to carry out his grandiose plan to sacrifice himself for the sake of Martha’s reputation. The look on Laila Robins’s face as Martha looks at Dennis, slumped forward in the car that will ferry him on the first step of his journey back to the United States and his eventual conviction for treason, is more terrible a weapon than any of the guns or knives wielded in this episode.

The one weak link in the episode is Fara’s death, which is dramatic and well staged but lacks the impact it might have had if “Homeland” had invested more time in developing her as a character. After Carrie’s return to the embassy, a devastated Max (Maury Sterling) tells her: “You were mean. All she wanted was your approval. And all you gave her was a hard time … You could have said something nice, just once. It would have meant so much.”

Max can describe Fara only in terms of her relationship to Carrie, because all that “Homeland” ever really let her be was a repository for other people’s senses of anxiety or responsibility. And while “Homeland” has made an incredibly impressive comeback this season, “13 Hours in Islamabad” is a powerful reminder that it is a much better show when it has the confidence to let Carrie be part of the ensemble, rather than be the whole show.