What happened to Sark this episode is almost exactly what happened to him in Season 2 finale; from being jailed to getting his face broken by Vaughn.
Sydney's full name is revealed to be Sydney Anne Bristow.
Number 47: The initiation date of Project SAB47 is 04/17/75 (Sydney's birthday).
Number 47: On the same document there other references, such as "NO. 938 JB/47" and "176847."
Number 47: On the document that Sydney read in the end was a name for the project "S.A.B. 47 Project."
Number 47: (hidden and reversed) Hank Foster says that Sydney was logged in at the safe-house where Nadia was being held at 7.22 p.m. (2+2=4; =74).
When Lauren points the gun at Sydney, she tells Vaughn "if you love her, you'll put the gun down". This same situation also happened in "Blowback," except that it was Sark who was pointing the gun.
When Vaughn uses the key to Jack's storage shed he grabs a rifle with a scope, Vaughn takes off the cap on the scope and then looks through it, however it would be impossible to see any thing because he didn't take off the second cap at the other end of it.
As Vaughn is escaping the hospital he pulls the folded firehose from its storage case. The next shot shows a nicely rolled hose falling down the stairwell.
When Sydney took the clip from Katya, there was no bullet chambered. Even if she left the clip in there would have been no bullet fired.
If you remove a full ammunition cartridge from a gun and hand it to someone, the weight will give away that the gun is empty.
EMTs wouldn't move someone stabbed in the back and suffering from a punctured lung, on their back on a gurney. Yet that's how they move Vaughn when they bring him in.
We have every reason to believe that Sark hacked into the CIA security feed when Lauren was infiltrating the rotunda. When on a view of the feed on Sark's laptop you can see the point where Lauren takes her Sydney mask off, meaning if the CIA has all of the feed there would be proof that it was Lauren and not Sydney who stole the equation.
The CIA investigators probably already knew the one inside rotunda wasn't Sydney, otherwise, they would have taken more severe actions than just questioning her. Their main suspicion stemmed from Lauren and Sark knowing Sydney wasn't in the facility, thus pulling off their fake Sydney infiltration; they wanted to know why she was conveniently away during the attack.
(Katya tries to shoot Sydney but nothing happens. Looks at Sydney, holding the cartridge)
Katya: How did you know?
Sydney: I didn't. Now I do.
(Sydney pulls of her Lauren disguise)
Sark: This little trick of yours means Vaughn failed. Tell me, is he dead?
Sydney: No, he's not. But thanks to you, Lauren won't be so lucky.
Lauren: Michael. Please, I need you to understand. When the Covenant asked me to marry you, I knew eventually they wanted me to coax you back into the CIA. But two years went by and I hadn't heard from them. And by then I'd convinced myself I never would. I prayed I wouldn't because I'd fallen in love with you.
Vaughn: Shut up! I am gonna erase you! I'm gonna remove any evidence you ever existed! You used me. You used my grief, my work, who I am. You took that from me – I'm taking it back. This is hydrochloric acid. You'll be unrecognizable.
Lauren: Michael, I swear I was gonna tell you everything. You remember that night we went downtown and had dinner? Instead you told me Sydney was back.
Vaughn: Don't say her name.
Lauren: She came back and you didn't need me anymore. I could see it in your eyes. Sydney came back and...
Vaughn: I said don't say her name!
Lauren: Sydney came back and I lost you.
(Vaughn shoots gun above his head.)
Vaughn: I hate you. But I love Sydney more. That's the only reason you're not dying tonight.
(Vaughn gets stabbed in the back.)
Lauren: Thank God.
Lauren: (To Sydney) You think the CIA couldn't find you when you went missing? Or that you learned what happened to you by chance?
Vaughn: Ready to talk?
Sark: Yes. When I first learned of your wife's true allegiance, I almost felt pity for you. How embarrassing it must've been to learn that the woman you shared your bed with was only using you as an unfortunate means to an end.
Vaughn: I wouldn't do this, if I were you.
Sark: But then, she wasn't sharing your bed lately, was she? She was in mine. Or in my car. Or the elevator. Or a garage. There is one time – this is my favorite – we were engaged in an alley and she called you to tell you she loved you. (Vaughn twists Sark's arm) That woman was deliciously filthy.
Vaughn: (To Sark) I'm not gonna kill you. That would be too easy. But I'll leave you so disfigured that when you walk down the street people will pity you. Lauren is gonna pay for the damage she's done to the people I care about, not for having had an affair with you. I don't give a rat's ass who she's sleeping with. So for the last time: where is she?
Lauren: We're both pawns in the same game. The difference between us is: I know who controls me.
Sydney: Who controls me?
Lauren: I guess you'll never know.
Nadia: When I was drawing, there were moments as the fluid wore off. I altered the equation. I didn't want to give you what you were looking for.
Sloane: Which means the Covenant has the wrong coordinates. They're looking for the sphere in the wrong place.
Nadia: We should go. We have a long journey ahead of us.
Lauren: If you kill me, you'll never know the truth.
Sydney: This is the truth. Sucks, doesn't it?
Sydney: You were right. Lauren has to pay.
Jack: Vaughn is going to be okay, and when he is, he has to end it, not you.
Sydney: If it's okay for Vaughn it's okay for me.
Sydney: In some twisted way, you've got Vaughn carrying your burden, trying to get you closure by doing the one thing you never had a chance to do, kill the person who betrayed you.
Jack: I did have a chance, and I didn't take it. And not a day went by that I didn't regret letting her go. Vaughn will feel the same way. He will end up like me, and I love you too much to let that happen.
Hank Foster: At seven twenty-two this evening, you were logged in at the safe-house where Nadia Santos is being held. Is that accurate?
Sydney: It was around dinner. I brought her a sandwich.
Hank Foster: Where were you before that?
Sydney: Buying her the sandwich.
(Vaughn knocks Lauren unconscious)
Vaughn: Hi, honey.
Vaughn: Last time we were together, our roles were reversed. Funny how things happen.
Sark: I'm afraid the irony is lost on me.
Lauren: If you love her, you'll put the gun down! (Vaughn puts it down) You really are a Boy Scout.
Lauren: (To Sydney) If your mother has really been helping you since she left, why haven't you spoken to her?
Vaughn: (To Sark) You like the electric batons, the injections... I'm not into accessories...
(Lauren is disguised as Sydney)
Sark: I must say, your disguise, it addresses a certain proclivity of mine.
Lauren: If this works, I'll happily make your sick little fantasy come true.
This episode was nominated for the 2005 Golden Reel Award for "Best Sound Editing in Television Short Form - Sound Effects & Foley". This episode was nominated for two Emmy Awards in 2004 for "Outstanding Sound Editing for a Series" and "Outstanding Stunt Coordination".
Isabella Rossellini was billed as Special Guest Star in this episode.
Jennifer Garner, Ron Rifkin, Michael Vartan and Victor Garber are the only people to appear in all episodes of Alias this season, and are also the only people to appear in every episode of the entire series this far.
Buffy Anne Summers was the full name of the title character of Buffy, the Vampire Slayer. A lot of people compare both shows, for obvious reasons. Some even say that Buffy's success helped Alias to actually exist as a show.
J.J. Abrams apparently rewrote the script a lot because he didn't feel that the original had everything that he wanted.
This is the first time J.J. Abrams has not written the season finale.
In this episode there are references to James Bond and Mission: Impossible. J.J. Abrams said during interviews that he was very much inspired by both franchises.
The original script for this episode (which JJ Abrams edited, as previously noted) involved an end-of-season cliffhanger with Sydney having to choose between saving Jack or Vaughn's life, who were both hanging precariously from a ledge.
Vaughn: I am going to erase you! I'll remove any evidence you ever existed!
In the 1996 film, Eraser, Arnold Schwarzenegger plays a U.S. Marshal who works for the Federal Witness Security Program "erasing" people's history so they can start again.
James Bond: Die Another Day
In this movie, Bond fakes cardiac arrest to get the doctors in, just like Vaughn did in this episode. It also ends the same, too. Both have the person taking the paddles before being shocked and instead shock the 2 doctors and escape out of custody.
Wearing a mask to disguise as someone else is classic Mission Impossible trick.