Person of Interest recap: 6, 741

It's the episode we've all been waiting for: the return of Sameen Shaw (Sarah Shahi).

But don't break out the Champagne too quickly because Shahi's homecoming isn't as a joyous of an occasion as one would hope. "6,741" reveals what's been happening to Shaw over the past nine months, and it's not pretty. In fact, it's downright frightening — but that's what makes it such a powerful hour. The episode's tone combined with Shahi's visceral and moving performance (her best on the show to date) and a heartbreaking twist ending make this the best episode of the season so far.

"6,741" opens with Shaw on an operating table as Samaritan doctors implant one of those mind control chips we first saw in season 4's "M.I.A." (which was coincidentally the last time we saw Shaw). Greer and his main man Jeremy Lambert hope the chip will make Shaw even more accommodating; however, the chip doesn't take, and Shaw manages to make her escape before they have a chance to implant another one. I love that the opening moments of the episode quickly make it clear that Shaw's personality hasn't changed. We find out that she's already killed several of Greer's men in the past few months and that her tongue is just as sharp as ever.

She makes it back to the city and pretends to plan the killing a poor drugstore clerk in order to get the Machine's attention and draw her teammates to her location because she can't go directly to them with that chip in her head. The plan works, and the look on Root's face when she finds Shaw in the middle of the store speaks volume about their relationship, which provides the episode with its emotional backbone.

After Reese and Root remove the chip from the base of her skull, they take her to a safe house where she's reunited with Bear and Finch. Her reunion with Finch, who is wary of her since Martine told them she broke months ago, hits a sour note when she accuses him of not coming to look for her. That's only one hint at some of the emotional baggage she's carrying from her time with Samaritan.

Once the boys leave, Root tries to put the moves on Shaw, but Shaw shuts her down. But then she changes her mind a few minutes later, and the two of them jump each other's bones to the sounds of Nina Simone's "Do I Move You," sending millions of shippers into a tizzy. Afterward, Shaw opens up about the psychological torture she endured while she was with Samaritan. Eventually, she goes to the bathroom and has a seizure as she touches the scar on her neck. When she finally comes to, she has a gun and ammo in her hands, which frightens her because she doesn't remember getting them. However, she decides not to tell Root about any of it.

By the time morning comes, Shaw has grown even more restless and reckless. She forces Reese and Root into going after Greer earlier than planned. They lure some Samaritan operatives to a location, steal their phones, and use the phones to find Greer's location. So Reese, Root, and Shaw storm Greer's hideout and capture him. If it seems like the episode is moving way too quickly to some big moments, there's a reason for that.

NEXT: A heartbreaking twist

With Greer in custody, Team Machine starts to interrogate him and finds a flash drive hidden in his arm. They extract it, and Finch discovers that it's a kill code for Samaritan and activates as soon as it's plugged into a networked device. So Finch and Root head off to handle that while Reese and Shaw, whose behavior has become a bit more erratic, keep watch over Greer.

Eventually, some Samaritan goons find them hiding in the church — an ironic place to hide from a godlike ASI — and Reese leaves Shaw alone with Greer while he handles them. Greer tells Shaw that this was all a part of their plan and that it's time for her to drop the charade and to let him go. Shaw can't believe it and has another episode during which she shoots Greer in the head.

Realizing that the flash drive is a fake, Reese and Shaw flee the church to find Finch, who gave his location when he plugged the flash drive in. However, Reese becomes suspicious about how Samaritan found them and knew that they were coming for Greer. So Shaw shoots him and leaves him to die. It's as upsetting as it sounds. She tells Root and Finch that Samaritan operatives killed him.

But, it's clear that Shaw is still fighting her programming, so she rendezvous with Root and takes her to a park instead of going back to Finch. There, she admits to shooting Reese and says she doesn't know who is controlling her. "Nothing's safe," says Shaw. In a tearful goodbye, she tells Root that she lied before and that when she was being tortured, she used to escape to this park with Root in her mind because Root is her safe place. Then, Shaw does the unthinkable: She shoots herself in the head.

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That's when the scene glitches and it's revealed that everything we just witnessed took place within a simulation that Greer and Samaritan created to force Shaw to give up the location of the Machine. She's currently unconscious and hooked up to a machine, and this was 6,741th time she's been through this. Each time she kills Greer, and each time she kills herself.

In general, I'm usually weary of "It Was All A Dream" episodes because I think they can be very gimmicky. But I didn't feel that way here because the narrative device was very much in service of character. "6,741" packs such an emotional punch because it's all about Shaw's relationship with her teammates. Even though she's unconscious, she's doing everything she can to fight back. She loves Root so much (and the team) that she has killed herself over 6,000 times so she doesn't have to kill her or lead Samaritan back to the Machine. It's a heartbreaking revelation that reminds me of the definition of love put forth by theologian Peter Kreeft: Love is the willing of another's good. That's exactly what Shaw is doing here. This all ties back to the theme presented in last week's episode — doing what's necessary to win the war. Each time she kills herself, Shaw is doing what's necessary for her side. The writers successfully turn such a trauma-filled story into one about friendship and loyalty.

The twist ending also reveals just how horrifying and dehumanizing Samaritan's tactics are. At the beginning of the episode, she tells Root that she realized there are no safe places in her mind; and that ends up being true. Samaritan is actually using her emotions and feelings against her. This episode makes it clear that she cares deeply for Root, but it's hard not to wonder if her decision to sleep with her was planned from the beginning and part of her programming.

The Even More Irrelevant List:

• Person of Interest‘s makeup team also deserves a huge shoutout for the work they did on Shahi today. By the end of the episode, she looked worn out, broken down and like she was fighting a fever she just couldn’t seem to sweat out.
• “Hi, I’m Stuart. You have beautiful eyes and gray matter. If I were a zombie…[slurping sounds].” —Creepy Samaritan doctor Stuart to Shaw when she comes out of surgery the first time.
• “John’s a professional dick.” —Shaw to Root and Reese when she finds them talking about her.
• “It’s hard to imagine both of us making it out of this in one piece.” —Shaw to Root right before they hook up.
• See Amy Acker’s eyes the moment Shaw puts the gun to her head. This was also a showcase episode for Acker.
• There are so many clues that this was taking place inside of her head: It was all told from Shaw’s point of view; the world glitched every time she touched the chip that was implanted; everything moved so quickly.
• Shaw’s many, many deaths remind me of the Machine’s multiple deaths.