Inside, Olivia uses her impromptu cover story as the basis for asking questions about Mitchell and his recovery, and Samantha changes the subject to ask what Olivia was doing in Marlborough. Working on a case," says Olivia. "What's the case?" asks Samantha. "Suspicion of a double agent," says Olivia, sucking all the air out of the room. Way to overplay your hand, Dunham. The kettle whistles, and Samantha coldly says she'll get the tea and Olivia excuses herself to go to the bathroom.
Meanwhile, Charlie's on his cellphone talking to a buddy, getting instructions. After hanging up, he explains to Charlie that his friend used to work at the phone company: "I never really understood why. The guy's a genius." Charlie makes a crack about how he wouldn't want to waste any of that potential, and maybe Charlie should take his attitude and hit the road instead of making fun of the person doing his dirty work for him. Anyway, the phone's been tapped, and Peter says they should be able to pick up any outgoing calls made from the home.
Like the one that Samantha's making now, to Mitchell, to tell him that Olivia Dunham is there: "She claims she was here to check on you." Meanwhile, Olivia's searching through bills and other documents in the drawers of a rolltop desk in the living room. Over at the Fringe lab, Peter's not having any luck listening in, so he calls his buddy Kyle back: "It's not working. All I'm getting is buzz. I don't hear anything." So Peter's going to miss the crucial part: Samantha telling Mitch that she thinks Olivia knows, with Mitchell doubtful but telling Samantha she needs to kill Olivia.
After a commercial break, we see Olivia's used her lockpicks to open the rolltop part of the rolltop desk. Samantha's arguing with Mitchell about the need to kill Olivia, saying her office might know she's there. Mitchell tells her it doesn't matter: "Dunham's already under suspicion for being unstable. They think she's dangerous."
Peter, meanwhile, wraps up talking to Kyle so he can try the phone tap again.
Olivia finds pictures of the giant cold virus in the desk, and makes a satisfied "I knew it!" face and glances towards the kitchen, where Samantha's listening to Mitch telling her (and now being listened to by Peter): "We can say she came after you, that it was self-defence." Samantha says there has to be another way. Mitchell: "There isn't, honey. There's one way. You cannot let Dunham leave there alive." Peter's eyes go wide, as Mitchell tells Samantha there's a gun in the entry closet. "Contact me when it's done," he says, and hangs up.
Peter hangs up and gets on his cellphone to tell Olivia, who, while Samantha grimly makes her way to the entry closet arsenal, is putting things back and rolling down the desk. Mitchell's also already on his way out of the office. Olivia's phone vibrates -- good thing she remembered to do that, huh? -- and she quietly answers. Peter tells her to get out of the house: "Samantha Loeb is going to kill you!"
Samantha gets the gun from the closet, which is just sitting under a sweater on a shelf and not tucked away anywhere or anything, and then starts stalking through the house, holding the gun up with both hands, which would be a little awkward to explain if Olivia happened to see her. She makes her way to the living room and then back to the bottom of the staircase. She looks upstairs, and suddenly Olivia is behind her, pointing her own gun at Samantha. She orders Samantha to put her gun down, and Samantha drops it on the floor.
Then Samantha gets all sad-eyed and blubbery about not wanting Olivia to hurt her, while Olivia yells for Samantha to get down on the floor. A warning shot is probably in order, but Olivia just keeps yelling while Samantha edges closer and is finally near enough to grab Olivia's arms and start struggling with her. It's a brutal knockdown dragout that features Olivia at one point getting a candlestick across the head. As she tumbles over a coffeetable, both she and Samantha scrabble for their guns on the floor and each come up firing. Olivia hits Samantha dead centre in the middle of the forehead, so it's going to be a closed-casket funeral for Samantha, who crumples, dead, in a heap on the floor. Olivia looks in horror at the bullet hole in the coffeetable, just inches from her.
Back at Boston Federal Building, the whole gang is going over Mitchell's work station, but there's nothing there, nothing they can trace. "Loeb knew he was going to cut and run," says Olivia. Broyles wonders if there's a way to track Loeb's cellphone, and Charlie says tech services tried everything, but Peter has an idea. He asks if the agents surveilling the area have seen any sign of Loeb, and Charlie says they haven't. "He doesn't know about his wife," says Peter, meaning she could still contact him. And just when you think Peter's talking about a dead reanimation-type thing, he just means they need Samantha's cellphone. Charlie says he's on it, because he takes orders from civilians now. Broyles is getting a team together. Everybody got their jobs? OK, break! I mean, never mind that it must be HOURS since Loeb told his wife to kill Olivia and he still hasn't heard from her. This is a great plan. "Nice work," Olivia tells Peter. "Thanks," he says.
So Loeb, driving, gets a text message from Samantha telling him to go to Clark and Commons. Since the rule in movies and television is that you are never lucky enough to already be heading in the right direction when you are told to go somewhere, Loeb has to pull a U-turn.
Olivia, Peter and Walter wait in Olivia's SUV by the payphone, all the better to watch and get on each other's nerves. Walter tells Olivia, "Peter was really worried about you when you were gone," and Peter gets annoyed: "Of course I was worried," he says. "He was really worried," says Walter, which earns a smile from Olivia.
So there's Mitchell, who's a little too unworried about whether there's an ambush there for him instead of his wife, who he hasn't actually spoken to in hours, since he told her to kill a federal agent. Anyway, the team converges on him, and he draws a gun, and gets a bullet in his shoulder from Olivia, who likely learned her lesson after not shooting Samantha. "You're under arrest," she tells him. Mitchell says nothing, just gives her a shit-eating smirk that angers Olivia to the point that she whacks Mitchell in the head with the butt of her pistol, dropping him like a rock. Well, that ought to impress Sanford Harris. In a reversal from the end of the last scene, Peter tells her, "Nice work." She says, "Thank you."
After a commercial break, Loeb's in an interview room, handcuffed with his arm in a sling, ignoring Olivia as she tries to string some information out of him: "I'd say to you that you have no idea how hard we're gonna come down on you, except you do," she says. Loeb says he wants to see his wife. He still has no idea! Guys, this is going to be so hilarious when he finds out!
Watching from the observation room are Peter and Walter, and Broyles and Harris, who sneers that Olivia won't get a confession. Broyles says all the evidence in Loeb's house was plenty, but of course it's not good enough for the Bureaucratic Douchebag over here.
In the interview room, Olivia's asking why they took her, and why they did the spinal tap: "Loeb, this is your last chance to cooperate." "Or what, you'll torture me?" says Loeb. See, he knows full well he's not on 24. Olivia asks Charlie to excuse them, and Charlie gets up and leaves. Poor Charlie's not wanted anywhere. "What's she doing?" asks Harris.
"You want your wife, Mitch?" says Olivia after Charlie leaves. He says he does. Olivia thinks about it for a moment or two before saying OK and pulling pictures out o