Principal Snyder talks to a cop after the fight, and they agree to say what happened was another "gang related violence," indicating that the Sunnydale police have been covering up vampire attacks for a while now.
Spike calls Angel his sire, an intentional misdirection to make fans believe that Angel was the vampire who sired him. When Spike uses sire he also mentions "Yoda", indicating that he thought of Angel as his mentor - the father-figure who taught him after he became a vampire. In interviews, Joss Whedon has stated that a "sire" can mean any vampire ancestor. So Spike can consider Drusilla, Angel, Darla, and the Master to all be his sires, even though he was sired by Dru.
At the end of the episode, Spike complains about "A Slayer with family and friends." Buffy's rejection of the typical "lone wolf" style of Slaying will come up frequently in the series, usually in the context of people questioning her competence.
When Sheila asks Buffy if she really burnt down a building one time, Buffy replies "Not exactly one time", referencing the previous episode where Buffy was involved in the burning down of an abandoned science building.
James Marsters (Spike) has revealed in interviews that he played Spike having an attraction to Buffy from the start, which is evident in the scene where he observes Buffy for the first time, on the dance floor at the Bronze.
Spike tells Buffy that the last Slayer he killed begged for her life. The last Slayer Spike killed was Nikki Wood. In Buffy the Vampire Slayer: Fool for Love (2000), we see Spike murder her, but we do not witness the exchange as the story unfolds, only through the Spike of the 1970s addressing Buffy in the present, and as such could be missing Nikki's pleas. Later in Angel: Damage (2004) we hear from deranged Slayer Dana that Nikki's plea was "Please, I have to get home to my son Robin".
When Buffy first encounters the Big Ugly outside the Bronze, she tells Xander to go get a stake. The script reads "Xander races to the table. Opens Buffy's purse, claws through lipstick, make-up, hair brush, a tampon! XANDER - Ahhh! He drops it like a hot tampon, finally finds a stake, runs."
Drusilla has a vision of Buffy in this episode and says, "It's dark" and "I can't see". Moments later the camera cuts to Buffy looking at herself in a mirror. Dru's comments about not being able to see her are made because Buffy is looking in a mirror.
An exchange between Buffy and Giles was cut from the original script for length: Buffy: "I don't suppose this is something about happy squirrels?" Giles: "Vampires." Buffy: "That was my next guess." Pop Culture References
The trivia items below may give away important plot points.
Joss Whedon originally intended for Collin, the Anointed One, to be the main villain of Season Two. This had to be abandoned because Andrew J. Ferchland's voice had begun to change, ruining his believability as a non-aging being. Thus Collin was killed off and replaced by Spike.
Spike, was originally intended to appear in only a few episodes of the Second Season. However, his character was immediately embraced and loved by Buffy the Vampire Slayer (1996) fans, which resulted in Joss Whedon's decision to keep him around longer.