The shot of what Knox is supposedly looking at in his microscope is random. It appears to be a spiral-shaped bacteria visualized at very high resolution. Although it could be part of a test looking for reactions of these spirochetes to the virus Knox and Fred discuss, it is unlikely. One would generally use cells closer to if not actual human cells to examine or confirm a virus' effect on people. The shot was likely chosen to represent the virus itself, but light microscopes (like the one in front of Knox) cannot resolve anything smaller than half a light wavelength, certainly not viruses. The microscopes that can see viruses, cannot observe live cultures: nothing would be moving.
In the last episode (the fourth season finale, "Home") the newly-reconstructed Wolfram & Hart had mostly white walls. Now there is wood paneling everywhere and the staircase is different.
Angel doesn't have his hair spiked anymore. This is the first time he's had a major change in hairstyle, in anything other than flashbacks.
When Lorne gets ready to read the Wolfram & Hart employees to weed out the evildoers, we get a quick glimpse at his clipboard. He has five categories in which to place each person: Okay, On the Bubble, Evil, To be Fired, & Yikes!
According to the package, Angel's mailing address reads:
C/O Wolfram & Hart
1127 Spring St.
Los Angeles, CA 90008
Fries declares that his case would have never reached a courtroom "when Holland Manners was running things". But Manners didn't run the LA Branch, or even the regular legal department; he was Executive Vice-President of "Special Projects". Nothing about Fries's case would seem to fall under that department (at least, not before he brought out the threat).
(after Angel kills Hauser)
Soldier: Whatever happened to mercy?
Angel: You've just seen the last of it.
Fred: I don't even understand half of what were doing. There's this machine, six feet tall that makes this noise, "whoompa whoompa pbbth!" Not a clue.
Angel: He said "drop the bomb." We don't know what that means.
Wesley: We very nearly found out.
Angel: What? I'm not allowed to hit people?
Wesley: Not people capable of genocide.
Angel: Those are exactly the types of people I should be allowed to hit!
Angel: You're my secretary!?
Harmony: Er Hello! Assistant!
Angel: Explain why I shouldn't kill you.
Harmony: Secretary is fine.
Hauser: You pathetic little fairy!
Angel: I'm not little.
Voice Mail: You have reached Ritual Sacrifice. For goats, please press "1" or say "goats." To sacrifice a loved one or pet, press the pound key.
Wesley: That's a powerful position for a young woman.
Eve: How exactly can you be sure I'm either of those things?
Wesley: So Knox, how long have you been.. erm.. evil?
Lorne: I think Fries Junior is about to become patient zero.
W&H Employee: I need you to initial here concerning your immortal soul.
Harmony: Creatures of the night.. unite?
Knox: He was fired... Oh, I'm sorry he was set on fire.
Corbin Fries: Butt-munch here, he got his law degree at dog-training school!
Harmony: (almost in tears) Cordy was my best friend, like... my whole life. She's my role model. How can she... (chipper) So anyway, I think you should not fire me, and Wes does too.
Lorne: Yes, that carpet is good because we want our clients to get dizzy and throw up.
Angel: You turned evil a lot faster then I thought you would.
Harmony: Blondie Bear?
Spanky: I don't spank men. It's not a judgement, men have fine firm asses. If you've been to the website you'll know how much I work on mine.
Angel: So it turns out with this new deal and all, I own a helicopter.
Angel: That's not a name I want passing through your lips.
Eve: And what would you like passing through my lips?
Angel: News flash. You're not cute when I'm angry!
Harmony: Now, before you go threatening to fire me...
Angel: I threatened to kill you.
Angel: Do you know what I'm doing now? Not using my windpipe.
Angel: Capital "V." And there's something else you should know about me. I have no problem spanking men.
Wesley: Your run-on sentences have got a lot less pointless.
Fred: That's so sweet! And, a tad condescending.
Fries: I say the magic word, the only people left standin' are gonna be the ones that are already dead.
Harmony: That's a relief. (everyone glares) I mean, 'Hey!'
Wesley: Feng Shui.
Gunn: What's that mean again?
Wesley: That people will believe anything.
Wesley: Don't you think it's a bit unseemly adding "Y"s to the end of people's names?
Gunn: Does that mean I have to call you "Wessle"?
In the DVD commentary, Joss mentions that for most of this episode the left side of Alexis' face is paralyzed due to Bell's Palsy. This is why the right side of Wesley's face is almost always facing the camera, though at some points you can see Wes smiling on only one side.
Corbin Fries is the name of Joss's nephew.
Alexis Denisof has explained in an interview about the spell Angel used to make the rest of Team Angel forget about Connor and how it affects Wes, Fred, Gunn & Lorne: They all still remember the events of last year but to them they turned out a little differently and some of it is a little hazy to them, they all remember that they were fighting a little last year (mainly Wes & Gunn) but they're willing to put their differences aside to concentrate more on their mission. This also explains why Wesley is still dark and broody - like he has been since after betraying Team Angel by letting Holtz take Connor.
The fact that this episode takes place so soon after last season's finale marks a major departure from the normal conventions of the series. Normally new seasons on both Angel and Buffy the Vampire Slayer take place three months after the previous season ended.
Some of the props from The Magic Box from Buffy the Vampire Slayer were recycled to be used in Fred's lab.
The score music in the background in the teaser of this episode has the same melody heard throughout "City Of'"(1x01), including the music heard during the very similar teaser of that episode.
David Fury has said that originally James Marsters was going to be a recurring guest star. However, while negotiations for season 5 were being made, The WB told the producers that if James became a regular the odds of Angel being picked up for a fifth season would improve greatly.
James Marsters (Spike) has been added to the opening credits, he is the third and final Buffy the Vampire Slayer star to join the Angel cast.
David Boreanaz is now the only remaining original Angel cast member.
Mercedes McNab reprises her role as Harmony after being told to leave by Cordelia at the end of "Disharmony" (2x17).
This episode marks the first time Joss Whedon has written and directed the season premiere since the pilot.
Charisma Carpenter and Vincent Kartheiser have been removed from the opening credits.
Lorne: The part's yours. Yeah, I've got a whole freezer full of horses' heads downstairs.
Lorne is telling someone that they will get a part of some sort, saying that "he has a freezer full of horses' heads". In the movie The Godfather, a man called Johnny Fontane gets a part in a movie because someone puts a horses head in the bed of the director who doesn't want Johnny in the movie, to scare him into giving him the part.
Spanky: I'm a big Our Gang fan.
Our Gang was the name of a series of short films created by Hal Roach which later became the TV series The Little Rascals. One of the main characters, in both versions, was named "Spanky."