Moscow: men are playing dominos. A sound is heard. People look up. Something crashes to the ground – a giant fireball.

Los Angeles: Weiss and Sid are drinking. Sid says there are advantages to losing all your stuff in a fire and dying and coming back to life. All the paper is gone. All the newspaper clippings and sweaters from high school. Weiss says there must be something that you miss. She says she had a first edition Alice In Wonderland that her mother gave her that she just loved. Weiss toasts Sid and babbles about Sid going to work tomorrow with Vaughn and Vaughn’s wife and him being there for her. Sid says it will okay.

Sid arrives at work and says hi to Lauren and Vaughn. Marshall rushes up. He has made her a CD of her music from the last 2 years. After much babble it is due to the music triggering thing sin the brain. Dixon rushes in. Moscow’s early warning system was triggered. It wasn’t a missile; it was a satellite crashing to earth. Russian missiles were activated – and then deactivated when they realized it was not an attack with two minutes to spare. A call was intercepted between Mr. Sark and Boris Seransky. Who was with the Russian space program. And has since been working for the French company who owned the satellite. He brought down his own satellite. On the phone call – Seransky and Sark discussed moving on to phase 2. Sid wants to be on the team if they are going after Sark. Lauren says that the NCS believes it can learn more about the covenant if it tracks Sark’s activities without apprehending him. Sid protests and begins arguing with Lauren. Lauren explains that the technology is different. Sid says it is people. She is familiar with the technique they did it with SD-6. As the argument escalates Vaughn tells them enough. Dixon sends Weiss and Sid on standard surveillance.

Lauren and Vaughn walk away. Lauren tells Vaughn she is done being nice. Vaughn tries to get Lauren to be understanding – saying that Sid lost two years of her life. She asks if she was different two years ago. Lauren tells him she is tired of walking on eggshells and that Sid is the most arrogant and condescending person she has ever met. Vaughn tells her she is reacting emotionally. Lauren says she is reacting logically. Vaughn says this was the first briefing. They might end up liking each other. But that no one blames her if they hate each other. Vaughn kisses her and says that he loves her.

Jack asks Sid how the briefing with Lauren went. Sid says just fine. Jack really wants to know – not for office gossip. He asks if she seems aggressive toward Sid. Sid says yes and that she was toward Lauren. Jack takes Sid behind closed doors and says that the NSC has convened its own investigation into the Russian Diplomat’s death. Sid asks if they know. Jack says that they have received additional footage of the crime. From a camera across the street. And as luck would have it Lauren has been assigned to the investigation. Sid says it is just a matter of time before they find out. She needs to get her memories back. Jack tells her that the techniques to regain her memory are invasive and surgical which could result in permanent brain damage. Jack tells her to do her job. To reintegrate into the CIA. Sid is going to Mexico City. Jack is going to help Lauren wit the investigation.

Jack and Lauren consult with Marshall on the film on Lazary’s death. We see the woman in a blonde wig. We see her kill Lazary. Lauren asks Marshall to freeze the frame and blow it up. The pixeling isn’t good enough to get an id. Jack tells Marshall he can do better. Marshall babbles then says he was made for this and to give him 72 hours.

Mexico City: Sid and Weiss are in the back of a van. Sid gets into disguise. Weiss reminds her they are there for surveillance only – nothing tricky. Sid wanders through a Mexican market. Sark is sitting at a table. A man approaches him and joins him. Sid snags photos of them. Sid says she is moving closer to get a look at the pics. Weiss cautions to be careful and not get too close. Dixon says they probably have backup. Sid shops for sunglasses and she listens to the pair talk. She uses a mirror to take photos of the picture. Seransky says that Sid is watching them. Sid runs. Sark says if she is CIA they should be leaving. Dixon orders Weiss not to help Sid. Seransky grabs a girl and holds a gun to her head. He tells Sid to appear or he’ll put a bullet in her head. Sid comes out and pulls a gun on him. His backup pulls a gun on her. Sid puts her gun down. Marshall tries to get Seransky’s RF signal. Vaughn reminds Sid of Thailand. Seransky demands Sid’s surveillance. Sid says no. Sid says the camera is in her glasses. She tosses the glasses over. Seransky crushes them. Seransky says they are going to walk out of there. Marshall gets the RF signal and puts a whine in Seransky’s ear. Sid overpowers him. A Fight ensues. Seransky gets away.

Los Angeles – Weiss and Sid fixing dinner. Sid says she remembers Sloane mentioning something about a project named Medusa. They talk about the myth. Sid gets all depressed. Weiss tells her that she wasn’t dumped. She says she hasn’t even asked how they met. Weiss tells her that they met during an investigation into Irina’s disappearance. They hit it off. Weiss tells her about their wedding. Weiss tells her that she is a good person.

Marshall shows Jack what she has come up with. Lauren comes in. The picture is clearer but still fuzzy. Lauren wants to feed the pic into a face recognition database.

Dixon says that Sid was right. Medusa was flagged in the SD-6 database. Marshall says something about a microwave signal transmitting across satellites and maybe frying them. Seransky was discharged before the project was completed. He had no idea what the status of the project was – until now. They crashed the satellite so that they could see what the Russian government would do if they were under nuclear attack. The satellite got photos of a motorcade going into the science ministry where they think there is a bunker and where Medusa is located. Dixon says they more information and to meet back later.

Jack consults with someone on fixing that photo. Jack pays the man and tells him he needs it now. Sid goes ballistic because they are talking about using Sloane. Dixon tells her Sloane is a necessary evil. Vaughn reveals that Lauren was on the team to broker his deal. They need Sloane to access the bunker. Dixon wants both Lauren and Sid to go. He doesn’t want to waste a minute if Sloane can get them in.

Lauren approaches Sid on the flight. She says she feels like she needs to acknowledge that it is a difficult situation and that no one would blame them if they hated each other. Sid admits that she doesn’t hate her of Vaughn. Vaughn says that they tracked Sark to a flight from Berlin to Frankfort but when the flight arrived, Sark wasn’t on it. Sloane says that he won’t help them. He is concerned what they will do once they gain access to the facility. He won’t help them break the law. He can’t risk putting himself or Omnifam into legal jeopardy. Sid says she has vowed to cause him great personal harm once he ceases to be of assistance to the CIA for information. Sloane gives in. He tells Vaughn that he knows how close he and Sid were and he must be relieved to have her back.

Moscow: Vaughn dresses. He and Lauren are on the list as Omnifam employees. Lauren ties Vaughn’s tie. The talk about somewhere they were at. Sid comes out. Lauren tells Vaughn to be safe and kisses him. She leaves to call Dixon. Sid leaves with Vaughn. The guy helping Jack that it is a polymorphic worm. It will corrupt the file. But it has to be done at a terminal with administrative privileges. Sid and Vaughn under the aliases are introduced to someone. They have about 1 minute until the guards change shifts. Sid and Vaughn gaze at each other across the room and she gives him that goofy lovesick smile. The guards are changing. Sid and Vaughn move into action. They plug in a device that takes the room into blackout for a moment. Sid and Vaughn make their way down a corridor. Vaughn uses a layover of some sort on his thumb to fake out a thumbprint reader. Marshall tells Dixon that the picture is almost ready and they can feed it into the face recognition database soon. Jack goes looking for Dixon. And uses the terminal in his office. Sid and Vaughn change clothes in the elevator. They then make their way down a hall in uniforms. Sid takes apart a panel of some sort. On the control room level – they see guards lying on the ground. Sark is there already, with Seransky. The elevator opens. A guard with a gun is on it. Sid and Vaughn get on.

Jack waits for the program to load. Marshall asks Dixon if Lauren briefs the President and could he get a white house tie clip? Sark orders that no one be allowed in the control room until Seransky calls. Sid and Vaughn get out of the elevator. A gunfight ensues. Marshall begins uploading the photo. Dixon’s assistant asks Jack if he found everything he needed. Jack says that he was just leaving a note. Sark taunts Sid from the control room and tells her that he looked for her upstairs. Sid fires at him. The glass is bulletproof. The elevator service is discontinued. They can’t steal Medusa. Vaughn says they can destroy it. But there is no way out. Sid and Vaughn blow something. Sark asks what that is. It is the generator. Medusa is fried. Sark leaves the control room. Seransky goes after Sid. Jack’s worm gets to the photo. Sid and Vaughn try to get out. Seransky begins screaming Sidney Bristow. They get out of a tube as Medusa explodes. Jack comes in and plays dumb on the picture to Marshall and Dixon.

Vaughn arrives back at HQ. He hugs Lauren. Dixon tells them that officially Medusa wasn’t in the possession of the Russians. Unofficially it has been destroyed. He tells the trio good work. Jack tells Sid that he took care of it and welcomes her back. On her desk, Sid finds Alice in Wonderland. Weiss tells her it is third edition. Sid says thank you and hugs him. He says that he will see her later.