In Release, Connor is seen in front of the mirror, checking himself for signs of vampiness. This scene was described in the script as:

CLOSE ON CONNOR as he bares his teeth, feeling for fangs. He relaxes into a normal face. Then -
A SERIES OF RAPID SHOTS: cut …

Lorne says of Lilah in Calvary (about the episode Slouching Towards Bethlehem in which his reading of Cordelia was stolen by Wolfram & Hart), “I haven’t forgotten how she poked my head open like a Capri-Sun”. He’s referring to the drink which comes in a foil pouch, often used in …

In the Angel episode Release, Fred is holding a tranquiliser gun and Connor says to her, “Thought you were more of a taser girl”. He’s referring to the episode Deep Down, in which Fred attacked him with a taser after discovering he’d harmed Angel.

Eliza Dushku’s brother, Nate Dushku, played the character who shoots the doughnut shop clerk in Orpheus. Nate has also appeared in Kiss Me Again, The Zodiac, Joan of Arcadia, Learning Curves, My Dinner with Jimi, Vampire Clan, Wolf Girl, Undressed, and Felicity.

In the Angel episode A Hole in the World, there is a reference to the Tim Burton movie A Nightmare Before Christmas. Angel looks to a large tree in England which he believes is the entrance to the Deeper Well. Spike states, “either that or Christmas Land”. In the movie, …

The character of Kate Lockley was originally going to be introduced in an abandoned episode called ‘Corrupt’, in which she was a cop deep under cover as a prostitute, and heavily addicted to drugs. This episode was abandoned two days before production was scheduled to begin, because the network said …

Wesley explains that the word “shanshu” means “to live and die” (in other words, to live a mortal life). The episode’s title, “To Shanshu in L.A.,” can then be translated “To Live and Die in L.A.” — the title of both a rap song by Tupac and a 1985 film …

Goof seen at 35:40 in Intervention

As Spike’s making his getaway from Glory, he heads towards the lift which pings and goes down. But who pushed the button for it? Spike wasn’t close enough to when it starts to move, and when he falls on top, through the hatch and it …

In the episode Sleeper Aimme Mann sings her song “Pavlov’s Bell”. The title of this song references Pavlov’s experiment with dogs, where he would ring a bell before giving them food. It got to the stage that every time the bell would ring the dogs would salivate in anticipation of …

Willow’s wishes for Buffy then a million dollars in Triangle could be a reference to the pilot episode of Friends - Ross says he just wants to be married again and Rachel enters Central Perk in a wedding dress, and then Chandler says he just wants a million dollars

Clayton Rohner played Las Vegas casino owner Lee DeMarco in The House Always Wins. He appeared in David Boreanaz’s show Bones as Wayne Kellogg and has been in Trespassers, Into the West, Jake 2.0, Coronado, CSI: Crime Scene Investigation, Jack & Jill, Charmed, G vs E, The X Files (as …

A sign in Las Vegas for Lorne’s show, seen in The House Always Wins calls him “The Green Velvet Fog”. This is a reference to jazz singer and song-writer Mel Tormé (1925-1999) who was known as “The Velvet Fog”. He co-wrote Nat King Cole’s Christmas hit “The Christmas Song (Chestnuts …

The cast and crew of Angel went on location to Las Vegas for this episode The House Always Wins. Though the action was set at the Tropicana, much of the filming took place inside the Riviera Hotel.

The title of the season four Angel episode Ground State comes from a physics term. Wikipedia says of ground state:

The ground state of a quantum mechanical system is its lowest-energy state. An excited state is any state with energy greater than the ground state. The ground state of a quantum …

Dinza is one of the Eleusian mysteries, the dark demi-goddess of the lost. Only the dead can enter her presence, and those that do, she often traps for eternity. Angel spoke with Dinza in an attempt to find Cordelia in Ground State.