Quietest night of the year: Halloween gets its name from the Catholic celebration of All Hallow's Eve, a day when all the saints, not just those with their own feastday, were honoured.
Its real origins go back much further, to the ancient festival of Samhain, the Celtic new year. On that day it was believed that the boundaries between the worlds of the living and dead were weakened. Thus spirits were able to cause trouble on earth, and humans to gain otherworldly knowledge.
For vampires, however, Halloween is just so tacky that they simply don't bother going out that night.
Sachs appeal: British actor Robin Sachs, who plays Ethan, appeared as Heinrich in the 1971 Hammer movie Vampire Circus. He's also featured in Jurassic Park - The Lost World and a couple of episodes of Babylon 5.
Retro toy alert: Cordelia compares Angel to a "Care Bear with fangs." For those of you who don't remember them, the Care Bears were a late-80's range of proto-Beanie Baby toys, with their own sickly, highly-coloured cartoon series. Amongst their roll-call were Bedtime Bear, Cheer Bear, Funshine Bear, Share Bear and Tenderheart Bear.
Blast from the past: Giles' old acquaintance Ethan Rayne calls him 'Ripper', hinting at a dark past that would surprise the Scooby gang. As would the abruptly vicious way he attacks Ethan.
Ooh, you're so two-faced: To work his spell, Ethan performs a ritual in honour of the god Janus. Always depicted as two-faced, Janus was an ancient Roman god, although his reputation wasn't really as bad as this episode would suggest. Actually he was a peaceful god of doorways and gates.
I'm not a number: The note that Ethan leaves behind on the counter of the costume shop just says "Be seeing you." Not only is this creepy in its own right, but it also refers to 60s cult paranoia drama The Prisoner.
Each episode, prisoner Patrick McGoohan would attempt to escape from the surreal Village, often only to find himself tricked by illusions. Could Mr Rayne be playing with Giles' head?
Freak out: Cordelia claims to have been attacked by JoJo the Dog-Faced Boy. A real person, JoJo was amongst the human oddities exhibited in the 1880s by P T Barnum. He suffered from hypertrichosis, or abnormal hair growth, which caused him to grow long locks all over his face.
The Friendliest Ghost : Willow wimps out by covering her lady of the night costume with a very modest ghost costume, prompting Xander to call her Casper. A sweet, cuddly little ghost, Casper was a cartoon character invented in 1945, who went on to have a long career on screen and in comics, including a 1985 live action film.
Given the way things turn out in Halloween, it was rather a good job Willow decided not to go with her original costume!
Hold on: If Willow is intangible as a ghost, who just passes through material objects, how come you can hear her closing the door when she leaves Ethan's shop?
Wrong type of princess: "She couldn't have dressed up like Xena?" gripes Willow about the useless noble-lady version of Buffy. Lucy Lawless' character from the cult New Zealand show Xena: Warrior Princess would certainly have been a lot handier to have around right then.
So macho: For a supposedly wimpy guy, Xander transforms very effectively into a battle-hardened veteran. He's even got that thousand-yard stare off pat.
Who's that girl? : At the end of the episode, Oz clocks Willow once again, this time in her risqué costume. He still doesn't know who she is though.