"Broken Hearts" is an intense -- if flawed -- episode of 'Homeland,' in which Carrie finds herself abducted by you-know-who, and Brody takes two steps back.

There's a moment in this week's episode that is so perfect and captures the internal moral struggles of its characters with such clarity that the resulting action feels that much more disappointing. Carrie's been abducted by Abu Nazir and is holding her until Brody can get him the serial number for Walden's pacemaker, which is ridiculous enough, but then you have this young Middle Eastern technician sitting in a lab somewhere in America, waiting to enter the code that will kill Walden. It seems that Nazir has always had plenty of possible ways to end Walden's life, and with the intelligence he's collected, Brody's involvement hardly seems necessary -- but maybe that's a part of the emotional bond that Nazir says he developed by torturing Brody, and maybe this is an extension of that relationship. Maybe not.

The moment I'm referring to comes when Brody swears on the soul of Issa that he will give Nazir the serial number as long as he releases Carrie first. After Carrie has been freed, Nazir demands the serial number, and Brody pauses with this face that's all silence and nerves, and you can just read so much in his expression -- how he considers that Carrie is safe and he doesn't need to kill Walden now, how he can say no to Nazir, and how maybe he can help bring this guy down once and for all. 'Homeland' is at its best when it does a few things: the interactions between Brody and Carrie, whose explicit feelings always hold this hint of dishonesty; the build-up of suspense via surveillance and connecting the dots; and the way the characters' morality is consistently challenged and presented in shades of gray.

When Brody pauses, it's so much of what I love about the performances from this cast, and how much can be said by saying nothing at all. But then he speaks, and then he acts, and then he sends the serial number to Nazir, which leads him to a confrontation with Walden, where he tries to tender his resignation and Walden proves to be the asshole he's always been. Brody keeps waiting for the pacemaker to fail, and just as it does he launches into this speech about how much he hates Walden, and he lets the man die. There is no gray moral area for Brody anymore -- he's made his choice, and it's not one that I think works so well with what this show's been trying to do, but I think the stuff that leads him there is more interesting, like the idea that you can only close the walls in so tight around a rat before it starts chewing its way out. I just wish he had chewed in a different direction.

We also get some more info from Dar Adul (F. Murray Abraham), who admits that Quinn is one of his, implying that Quinn is there because Saul is the kind of agent who doesn't like getting his hands dirty. Saul tries to get the straight story from Estes, correctly inferring that Quinn is there to kill Brody and make sure no one finds out about the drone strike cover-up -- and at the end of the episode, Saul is being pulled away from his team (who are all heading out to the abandoned mill where Nazir kept Carrie) and sent to an interrogation room. We can assume this is because Saul, unlike our other major characters, has a pretty well-defined moral compass, and I look forward to seeing how the CIA sees fit to handle that next week.

In minor happenings this week, Jessica and Brody share a moment where both of them wonder what the hell they're doing together, which means this plot is finally going somewhere. Dana meets with Finn, who just wants things to go back to the way they were before he hit and killed that woman with his car, but Dana is resistant and tells him that things can't be different and that moment changed everything -- this plot point has been up and down all season, and while not entirely successful, I can appreciate the parallel between the hit and run incident, which has fundamentally changed Dana, and Brody's decisions with Nazir, probably going back to the moment when he decided to accept Nazir as his leader. It's not a subtle point, but I enjoy the attempt at trying to show how life-altering a single decision can be -- it seems so hard sometimes to get to the point where you make a decision, but once you do, you find it's so easy to just take the action or say the word, but then everything will forever be different and you can't take it back.

Brody has a chance to take it back and help the CIA. He could have told Saul that Nazir had Carrie. They could have worked out a plan together. But he chose to make a decision based on both fear and his own personal resentment.