When Angel punches Lorne, Gunn moves over to Fred, pushes her out of the way, and Fred runs off to his right. The shot then changes to a closeup of them and Fred is back on Gunn's left and he once again moves over to her and pushes her out of the way to his right.
When Liam and Cordelia are in her room, and after Liam almost bites her, he runs into her bathroom to look into the mirror and check if he's a vampire. How did he know where to go? At the early 18th century, bathrooms in private houses were very uncommon and could mostly be found at very large mansions or palaces, and Liam's family didn't seem to have that much money (see episode "The Prodigal" 1x15). And anyway, in 18th century, mirrors weren't usually placed in bathrooms.
Cordelia says "Hello salty goodness" when she sees Angel. This is the same phrase she used when she first saw him in the Buffy the Vampire Slayer episode "Never Kill a Boy on the First Date" (1x05).
When Gunn punches Wesley, the camera cuts to Angel and Fred and it appears that the two actors are trying not to laugh.
While demonstrating her "super power" to Angel (screaming her head off), Cordelia's hair has come loose from its barrette and is hanging down the side of her face. A few moments later Connor saves her, and when she's talking to him afterward, her hair is pulled back again.
Wesley seems pretty ready to send Liam and Cordy off by themselves when in their reverted personas they both just found out vampires exist and have no idea how to kill them.
When Gunn and Wesley are fighting, Angel has his arms crossed, but when it immediately cuts to a close shot of he and Cordelia, his arms are to his side.
Angel/Liam reacts to the "minstrels" on the radio and panics when seeing the cars, but isn't bothered at all by all of the electrical lights.
Lorne and Fred speak in "Pylean". Except when the gang was in Pylea the natives didn't speak anything but English, both to the Earth-types and to each other.
In the recap at the beginning of the episode, when they redo Cordy asking "Were we in love?" Angel is unhurt. In the previous episode in the original verson of the scene, Angel was cut and bruised.
Charisma Carpenter actually asked the staff if she could cut her hair, and they said no, because they knew the show would be a "to be continued," but on the first day of shooting, David Boreanaz walked in with his hair cut.
When Wesley and Fred are in the kitchen and Wesley's "sharp" stake pops out, he pushes it back in with the palm of his hand, with no pain.
Angel: You're stronger than the rest. Are you not a vampire yourself, then?
Connor: You don't remember?
Angel: I remember waking up here in this madhouse with that fine lot of hypocrites.
Angel: I'm supposed to be evil, but they attack me without cause. They gang up on me because I'm different. They're as bad as my father.
Connor: Fathers. Don't they suck?
Cordelia: You have no idea how much this is killing me. I know my ABC's, my history. I know who's President, and that I sort of wish I didn't. I know the name of every shoe store in the Beverly Center, but I don't even recognize the sound of my own name.
Angel: I seem to be strong, too, and fast. It's not so bad, this vampire thing.
Cordelia: Well, I've got a super power of my own, hotshot.
Angel: What's that now? (Cordelia screams at the top of her lungs) That really is inhuman.
Wesley: So who are you?
Gunn: I'm the guy that's gonna be kickin' a whole mess o' ass somebody don't tell me what's goin' on.
Cordelia: Whadda they call you for short?
(Angel, not remembering he's Connor's father)
Angel: Say one thing, then..."Be good. Fear God. Do as you're told." And the whole while I know good and well, (my father's) had his share of sinning.
Connor: Sounds kinda like my father.
Angel: Is he a self-righteous bastard?
Connor: You'd be amazed.
Lorne: (Waking up) Oh...Oh...Guys, hey, that was quite a whammy. A little trip through the transitive nightfall of diamonds, if you know what I mean, I certainly don't, but—
Angel: He speaks madness.
Lorne: Hey, here's a funny sidebar. I'm tied to a chair—again! What the hell's going on?
Wesley: We were hoping you would enlighten us, spawn of evil.
Lorne: Oh, dear. I'm starting to suspect my surefire hit spell closed out of town. (whimpers) Did anything go right? Anything? Did Cordy at least get her memory back?
Wesley: Just tell us where the vampire is, fiend.
Lorne: What are you talking about? There aren't any vampires here. Well, I mean, except for our boy here.
Angel: Uh, lying devil man.
Lorne: Oh, like my spell made you not a vampire anymore. My magic isn't that—
Angel: Shut your face!
(punches Lorne, cuts to Lorne narrating)
Cordelia: Maybe I was gonna tell you to back off, buddy. Maybe you were coming on too strong—harassing me in the workplace. Maybe I had a red-hot restraining order in my mitts. You ever think of that?
Angel: I was never—in the workplace, I— Well, there was that one time with the—the ballet and the stripping and the roundness, but that was a spell. And-and we were meeting in Malibu on the bluffs at night. That's a pretty romantic restraining order!
Angel: (to Cordelia) We'll get you back. No matter what. I promise you, we will get you back.
Lorne: What's all this "we", pale face?
Gunn: What the hell are you talking about?
Cordelia: It's called kidnapping a minor, hair club for men.
Wesley: Where do you hail from, friend?
Angel: I'm not your friend, you English pig.
Angel: (sitting on the stairs, muttering to himself) English pig. English pig?
Gunn: Great. So we go vamp hunting. This place looks pretty big. I say two groups.
Cordelia: (about Angel) Great. I'll go with tall, dark, and slightly less pathetic than you two here.
Wesley: All right. I'm going to let you all in on something you may have trouble comprehending. But I assure you that however...
Gunn: Vampires are real.
Wesley: I was telling!
Wesley: Well, I know this breed is nocturnal and feeds on roots and possibly human effluvia... It's a horned race...
Gunn: So you know jack?
Wesley: They're nocturnal?
Gunn: The day I take orders from guys like you is the... day I... (scoffs) Not even gonna happen.
Lorne: (about Connor) Poor kid. Engine running and stuck in park.
(about Wesley and Gunn fighting)
Cordelia: Are you going to get in there and stop it?
Angel: It was about time that the English got what's coming to him, I'm rooting for the slave.
Fred: I'm ready, I'm okay, it'd be cooler if we could score some weed though.
(Gunn and Wesley start fighting over which one of them should be in charge of the situation. Lorne looks up and addresses the audience)
Lorne: Look, I know I'm supposed to be unconscious during this segment, but can you believe these two mooks?
(A radio plays in the next room)
Cordy: uh (turns off radio)
Angel: How...? You stopped the tiny men from singing.
Fred: Are you sure this is going to work?
(Lorne says something in Pylean)
(Fred answers him in Pylean)
Fred: Its Pylean. He said "My words will work miracles" and I answered "May your words please the gods".
Lorne: (in the nightclub) She didn't say "may your words please the gods" so much as she said "may you orally please the gods".
(When returning to the show after the commercial break)
Lorne: Well those were some exciting products, am I right? (applauds) Let's all think about buying some of those.
Cordelia: Oh, God! Oh, God! My hair! My Hair! (sobbing) The government gave me bad hair!
Gunn: What happened to you, man?
Wesley: I had my throat cut and all my friends abandoned me.
Cordelia: (to Fred) Oh! We're both in school. Oh gosh! Let's be best friends, so I can lose all my cool ones.
Wesley: There's no call to be snippity, miss.
Cordelia: This is a Clarion call for snippity, Princess Charles.
Wesley: It's Wesley, thank you. Wyndham-Price. I attend the Watcher's Academy in Southern Hampshire. In fact, I happen to be Head Boy.
Cordelia: (sarcastically) Gee, I wonder how you earned that nickname.
Wesley: A lot of effort I don't mind saying.
(Wesley is fiddleing with his arm weapon and accidently fires a small dart which hits Angel in the leg)
Wesley: Are you okay? Oh! I mean Ha!
Angel: Cordelia - Were we in love?
Cordelia: We were.
Wesley: What type of demons, would you say?
Fred: Got any weed?
Fred: I sorta see his point. Not one of ya'll looks exactly seventeen. It's like time's been pushed forward, like we missed a bunch of years.
Cordy: (looking down) Kind of have filled out even more.
Fred: (likewise) And... I apparently ain't gonna.
Cordy: Okay, we've heard from Scarlett O'please-shut-me-up.
Gunn: (introducing himself) Gunn.
Wesley: (ducking) Where?!?
Wesley: The cross obviously doesn't affect me, or our friend, the pugilist.
Gunn: Oh, your ass better pray I don't look that word up.
Lorne: It's always nice to hear the mother tongue, as long as its not from my mother.
Gunn: Oh good, symbols on the floor. That always goes well.
Lorne: So I'm an idiot. What are you, perfect?
Angel: I guess I'l start feeding on your corpses now. Starting with the girls. So hard to choose..
Cordy: What do you mean hard to choose...I mean eat her (points to Fred) she's the tasty one..look at her, half of her is neck!
Joss Whedon states in the Season 5 DVD featurette "To Live and Die in L.A.: The Best of Angel", that this episode is one of the best episodes of Season 4 and of the series as a whole.
The song Lorne is singing at the beginning of this episode, "The Way We Were" by Barbara Streisand, is the same song Harmony sings at the karaoke bar in "Disharmony" (2x17).
If you study the scene in which Liam runs in and yells, "Demons!," if you watch Alexis Denisof and David Boreanaz closely, you see they do not meet eyes in this scene. This is because every time they did, they would burst into laughter, so they had to avoid looking at each other.
Andy Hallett (Lorne) is credited as "Special Guest Star Andy Hallett."
The spell to regain Cordy's memory originally had more explanation, but it was cut due to its length.
Lorne: Now, we represent the six spheres of consciousness, the six gifts from the Lords of Shah-teyaman, the six walls of the house of truth. We're all one with Cordelia, we bring to this circle only trust and imagination. The bottle in the centre of the circle contains the liquid essence that has passed through the wraith and been gathered here...
Gunn: We're curing Cordy with a urine sample?
Cordelia: Okay, not drinking it...
Lorne: Hush, puppies. All we do is join hands and concentrate. On the bottle, on Cordy, on calling her back to the way she was.
This is the only episode of Angel this season that Joss Whedon both wrote and directed. The idea to make it came from a discussion he had with Alexis Denisof and wanting to see nerdy, loser Wesley again.
Although he has no lines, and only his eyes are seen, Vladimir Kulich is credited.
Lorne: Who's we, paleface?
Lorne is alluding a classic joke featuring The Lone Ranger and his faithful companion Tonto. The Lone Ranger and Tonto are surrounded by hostile Indians. The Lone Ranger says to Tonto, "Old friend, we're really in trouble this time." Tonto replies, "What do you mean 'we', paleface?"
Cordelia: Okay, we've heard from Miss Scarlett O'Please-shut-me-up!
This alludes to Scarlett O'Hara, the main character from the famous Civil War era book "Gone with the Wind" by Margaret Mitchell.
A minstrel was a European bard who performed lyric poems while playing simple instruments. Occasionaly they would travel in small groups, each with different instruments. This would be the closest thing in Liam's experience to modern music, with a singer backed up by an instrumental band.