When they first show Buffy’s basement in season two’s What’s My Line, Part Two, and everytime thereafter until season six’s Flooded, the stairs leading down are solid concrete. But in Normal Again they’re suddenly wooden, with spaces in between the stairs (as seen when Buffy reaches through and trips Tara). …

In Bewitched, Bothered and Bewildered, when Xander and Cordelia are hiding in Buffy’s house, Xander says it should be safe in there. Angelus appears suddenly at the window and says “Works in theory” before pulling Xander out of the house. Angel says the same line in the Angel season three …

It is widely believed in the fanfiction community that the episode Superstar was a nod to the creators of Mary-Sue fiction. Mary-Sue’s are fan fiction stories where a new character (often an idealised version of the author) is crowbarred into the narrative, usually destroying the plot-continuity. This character is the …

Joss Whedon appeared as Numfar in the Angel season two episode ‘Through The Looking Glass’. Joss had the idea of Numfar dancing the dance of joy and showed how it should be done, it was then decided that Joss should perform it himself. Andy Hallett (Lorne) didn’t know who it …

In Primeval, Joss Whedon got the idea of the Scoobies combining their powers to make a super-Slayer to defeat Adam from the Promethea series by Alan Moore.

In Surprise when Angel gives Buffy a Claddagh ring he tells her to wear it with the heart pointing inwards to show that you belong to somebody - like he is wearing his. If you look closely at Angelus’ hand in I Only Have Eyes For You (when he is …

In First Date, when Buffy and Wood are fighting the vampires in the alley, a vampire walks round a corner. This is a re-used shot from The Gift. It is the same vampire that Buffy killed at the start of The Gift when the vampire followed the teenager into the …

In the original script for Lie to Me, Chantarelle’s (later Lily and Anne) name before changing it was Joan.

In First Date, Giles finally explains how he escaped from the Bringer in Sleeper:
“It was extraordinary good luck, of course, and training - years of training… But I honestly feel the largest part of it was instinct. Instinct and reflexes. There’s a sort of wary watchfulness I’ve developed over …

In First Date, Principal Wood says “I guess we should talk” after Buffy sees him fighting the vampires. In Hush, Riley said, “Well, I guess we have to talk” after he and Buffy discovered each others’ demon-fighting secrets.

The revelation in First Date that a Slayer had a child is a new one to Buffy, who believed that most Slayers died before they reached an age to have kids. We learn that children of Slayers don’t inherit any powers from their mother, but they do like a good …

We discover in First date that the First cannot be recorded. Andrew wears a wire to try and record the First in First Date, but only results in angering the non-corporeal evil.

In First Date, Buffy mentions the girl who Spike took as a date to Anya and Xander’s wedding in Hell’s Bells: “You should try this, too. The going-out thing, I mean. There was that girl you brought to Anya and Xander’s not- a-wedding.”

In season seven, Joss Whedon stated that he wanted season seven to go “back to the beginning”. A small bit of continuity is the title of the episode First Date, which is the same as the last two words of the season one episode Never Kill a Boy on the …

Chao-Ahn was a potential Slayer from Shanghai in China, first seen in First Date. Buffy told Xander that Giles was picking her up at the airport in Potential so she must have gone on the vision quest field trip in The Killer in Me. She spoke no English and none …