We open to Sid running and rock music. She stops. Sloane says hello t her. He tells her the Covenant is about to make a move. She tells him to make a call to Lauren. He says she is capable but that she cannot comprehend the need to lie. That Sid's ability to look him in the eye and lie to him was amazing. He says something about it being for old time's mistake. He misses her. He misses Emily. He misses the friendship with her father. He misses her confidence and trust. Perhaps he can get it back someday? She says that he will never have her confidence or trust or her father's friendship and respect - ever.

Switch to Vaughn and Weiss in hockey gear on ice. Vaughn begins making a series of shots at the goal. Weiss says that his brother used to do that. Brood and get all mopey. Then finally end up telling him what he was mad about. Vaughn talks about it being two weeks since he found out that Sid murdered Lazaray. Weiss says that he has to. Vaughn doesn't like it and says that her job is to find out who murdered Lazaray and he is keeping her from doing her job. Weiss says that this is why people from the CIA shouldn't marry people from the NSC. Don't poop where you sleep man. Vaughn gives Weiss a nasty look then makes a wicked shot at Weiss.

Sark meets with someone in a van. It must be done in a certain way. His partner has been briefed. Sark says partner he doesn't think so. He is told this is not a request. If he doesn't trust him by now he should be in business with someone else and to pass that on to ??. The man laughs.

Dixon briefs the team on Robert Lang who designed something Russian. He was approached for something. Marshall babbles about what he designed. Sid says it is a skeleton key for Russians nuclear weapons. They show a picture of what he used to look like. His appearance has been surgically altered so he can hide from The Covenant. Then there is something about Heinrich someone who is in Milan picking up new identity papers. Sid and Vaughn need to find Lang. Dixon says that given the current circumstances, they need to make a change. Sid is to take over as Sloane's handler. Sidney says that isn't necessary. Lauren protests. Dixon tells them that Sid is more familiar with the players. Sid says just Sloan and Sark that's it. Dixon tells her that Allison Dorne is alive.

Sark is shoved out of the van. The guy says he can thank her later. Sark stares at Allison. They kiss. She says he looks like he's see a ghost. Later they are in bed. He thought she was dead all this time. She tells him about Will finding out she killed his girlfriend and was doubling her all this time. We see a flashback to that. Sark asks about what happened to Bristow. When The Covenant found them they were both unconscious. She only remembers bits and pieces - more flashbacks of the fight. She realized that she knew. She aimed the gun at her. The next thing she remembers it was 3 weeks later and she was in a Covenant hospital in Marseilles. She's been working for them ever since. He asks if she was behind them extracting him from the CIA. She says that she wishes she had. She only learned recently of his working with them. He says they brought him in because of his father's murder. They freed him in exchange for his inheritance. She asks who killed his father. He doesn't know but he intends to find out. He runs his hand over her scars and says Bristow should have to pay for these scars. Allison says she will. They kiss.

Lauren tells her superior that Dixon gave the job as Sloane's handler to Sid. He says good it frees her up to focus on the Lazaray murder. They have information from the Russians. She ponders why they aren't using the information they have to find the murderer. The guy says that The Covenant does not want it know that they are behind the murder. Lauren says that The Covenant's reach inside the Russian government is so deep that they can make that happen. She leaves tonight. Any leak and their source will be compromised. She has to keep this from her husband.

Lauren packs for Vienna while Vaughn packs for his mission in Milan. She tells him she has to go to a security briefing. Lauren says that when they get back and are done with this they need to get away.

Lauren meets with a man. He asks how a British woman got to be an American spy. She says she was born in America but raised in Britain. He gives her the information. His loyalty is still to the covenant. He hands her a recording of phone calls the Lazaray. He hopes that one of the calls can be traced to the murders. She asks how they can contact him. He says they can't. They never had this conversation.

Vaughn babbles about the camera Marshall gave them. Sid comes in. The camera will identify Lang. It sends pictures back to his PDA. She talks about Allison being alive. She wonders if she still looks like Francie. And as much as she wants her alive to find out where she has been, she will kill her.

Sark hands an envelope to Allison and says Heinrich Strauss. AS they speak he is getting drunk in the club. Back to Sid and Vaughn. The camera is in a necklace. Vaughn puts it on Sid. Allison preps a rifle and says let's go. Sid is in a club. Vaughn tells that they are looking for someone about 5'10" 170 lbs. She checks out various people. They finally find him. He gets his identity papers. Someone has a laser site on him. He is shot. Sid says Allison is the shooter she's in the balcony. Vaughn is on it. There is chaos in the club. Sid dives over the bar. Vaughn is on the balcony. Lang flees. Allison takes off. Sid goes after Lang. Vaughn goes after Allison. Allison drops through the top of the elevator. She chokes Lang. He screams. Vaughn get to the elevator shaft. He tells Sid she's in the elevator with Lang in the basement. Sid approaches the elevator. Lang is dead. Allison hits Sid on the back of the head.

Sid ponders to Weiss why she didn't kill her. Weiss says that maybe she likes her. Sid says she thinks it is that she was ordered not to kill her. Vaughn wants to know how she survived getting shot 3 times 2 years ago. Weiss asks she took the guys tooth? Sid says yes. Lauren joins them. They have checked his records for things. Lauren realized they already had Lang's x-ray - from the camera - the pic Sid took. Weiss says nice. Lauren has to leave. Vaughn walks her out.

Marshall analyzes the x-ray. The tooth was actually an RFID tooth. A radio frequency ID. They think he used the tooth to open a vault or briefcase. Sid says Sloane is their man with the covenant and assumes that there is a lane waiting. Lauren gives the tape to a tech. She tells them to run it through voice identification.

Sid arrives in Zurich to see Sloane. He says he was pleased when Dixon said she agreed to be his handler. Sid says that it was an assignment. She will design the missions. She will control what he does. Sloane asks if that is what Vaughn did. Sid tells him about the device and that he needs to get it from Allison. Sloane say he wondered when she would resurface. She tells him he will meet with Sark and Allison and tell them they have been compromised and arrange assistance to them. Sloane will be wearing a wire. Sloane asks what if they find out it is a set up? Sid says she gets to hear them kill her.

The tech plays a call back for Lauren. The call is a day before the murder. An appointment is set up for the time of the murder. The tech traced the call back to Knightsbridge in London. The voice was digitally altered. Lauren is in London. She finds the office where the phone call originated. It is empty. A four-year lease was paid in advance. The person's name is Julia Thorn.

Sloane meets with Sark and Allison in Prague. Sloane says he feels like a field agent again. Allison says that she looks like someone else. When he said they needed her for gene therapy he promised that they could reverse engineer the process. Sloane says that Sidney destroyed the process. Sloane gets down to business and tells them that the CIA is on to them. They know that they extracted an RFI chip from Lang. They have their plane under surveillance. He suggests they move up their timetable. He will provide a plane for them. Allison says he is lying. Sark says she is a wonderful judge of character. Sloane says that Sid found her in Milan and if he were a betting man she'll find him again. Sark says they are going to Bulgaria. The vault is in Sofia. Sid orders Sloane to find out where she has been for 2 years or she will put loud feedback through his receiver and he'll be outted as a double agent. Sloan says that seeing Allison reminds him of what happened two years ago. He wonders if they have crossed paths in the last two years. Because she had the opportunity to kill her in Milan and didn't take it. Allison says The Covenant wants to retrieve something. Something in Sid's memory. Allison does not know. Something she saw.

Sid talks to her father again about retrieving her memory. Jack reminds her that these procedures are surgical. She says she is losing her mind. She needs to know. Dixon comes up. He just got off the phone with a contact in Sofia. Once Allison's plane lands they will track her until she gets to the vault. Dixon tells her to leave at once. (Leave at once? Why did they return to the US if they knew that Sark and Allison were going to Bulgaria? Sounds like a waste of taxpayer dollars to me.) Dixon asks if there is a problem with that. Jack says no. He leaves to go over the op tech with Marshall. Dixon asks Sid if she is clear on the rules of engagement. Sid says that she is another contact to The Covenant so she must try to bring her in alive. Dixon says no. She is to bring her in dead or alive. She killed his wife, and Sid's friend. This is an opportunity. The only reason he hesitated before was for her - she might have info. Now that they know she doesn't, he wants that bitch dead.

Marshall talks to Vaughn. He's using the tooth. The device will lead them to the chip. Which will lead them to the vault. He didn't know the exact frequency so he had to broaden it. He suggests they steer clear of microwave ovens. Marshall asks Vaughn for advice on proposing to Carrie. Marshall gets behind a drum set and plays as he chants a little song. Then goes into a full drum solo. Vaughn is grimacing. Marshall looks at Vaughn and says no good. Vaughn says she'll say yes, in spite of the rock song.

A chopper flies over Sofia. They spot Allison. It is abandoned. Looks like a hotel. They get the address and order the chopper to set down. Vaughn and Sid hit the ground. The signal indicates she is in there. They walk through the empty building. Allison walks through as well. There are lights on (inside an empty hotel??). Vaughn and Sid track the signal. They find the tooth but not Allison. They can't track her without the chip. They split up. Sid follows her into the west stairwell. Allison knocks Sid down and pulls a gun on her. She says she went over this all night long. Would she follow orders or not follow orders. She says sorry about her friend but once she was doubled she had to be murdered. We see a flashback of Francie at her restaurant. We see Francie and Allison face to face. We see Allison shoot Francie. She had nothing against her she was a casualty of circumstance. She tells Sid not to blame herself she had no way of knowing. Just like she didn't know that when she recovered Rambaldi's journal she had no way of knowing she also recovered a formula. Sid asks what she is talking about. A formula for a medication that would ultimately heal her wounds. So she killed her but saved her life (could the same formula have been used on Sid?). Sid and Allison fight. They aim at each other. Sid fires. Vaughn and back up come running in. Vaughn recovers the device. Sid says that she shot her. But they had a pulse. They've taken her to a hospital in a civilian ambulance with an armed guard. Dixon will call about getting her extradited. He wants an update on her condition. Vaughn speaks to someone in French. The ambulance left 20 minutes ago but the hospital is only 10 minutes away. They aren't responding. Sid runs up to Vaughn. She asks if he remembers a formula for a medication in the Rambaldi book. He doesn't. They have to find that ambulance. They follow the route. There is a man laying in the road and an abandoned ambulance. The ambulance is empty except for a dead man's body. Sid thinks that she did this herself that she didn't have back up. Vaughn says she barely had a pulse. Sid says she did this Vaughn. She did this.