The episode was written by story editors Matt Kiene and Joe Reinkemeyer, and directed by Bruce Seth Green.
When Buffy and the rest of Sunnydale High endure the annual field trip to the zoo, Xander and some other kids sneak into the quarantined hyena exhibit, but leave in an altered state.
When Principal Flutie (Ken Lerner) interrupts, Lance doesn't denounce them, so they decide to include him in their exploration of the off-limits hyena exhibit.
At the exhibit, the bullies try to throw Lance into the pit, where a vicious hyena with glowing green eyes appears.
Buffy admits to finding him attractive but says she can't start a relationship with someone who's rarely around and whose main interest is fighting vampires.
As Flutie talks to Buffy about the students lacking school spirit, Xander walks past, and Herbert suddenly starts squealing.
This phrase takes Buffy back to her conversation with the zookeeper, and she believes his change is the result of their trip to the zoo.
Giles returns from a teachers' meeting and tells them Flutie has been eaten alive, but the official theory is that wild dogs got into his office.
The zookeeper tells Giles and Buffy he discovered the hyenas were a vicious breed worshiped by the Primals.
On the street, the pack attacks a family of three, but Buffy arrives and gets their attention, making them chase her back to the zoo.
She agrees to let the zookeeper tie her up and hold a knife to her throat, claiming it is the "predatory act" that will trigger the ritual and save the students.
The next day at school, Xander is shocked when Buffy and Willow tell him that he ate a live pig, claiming he has no memory of the possession.
As Buffy and Willow leave, Giles tells Xander that none of the research he did on animal possession mentioned memory loss.
Theresa Basile, in a series about consent issues in Buffy, cites Buffy as telling Willow that Xander "tried his hand at felony sexual assault," but points out that "he does believe that she's attracted to dangerous men – that if he were dangerous and mean, she would be attracted to him"; and this is "before they find out that Angel is a vampire."
"[3] Reviewer Billie Doux, giving a rating of two out of four stakes, suggests a comparison with Lord of the Flies and calls Nicholas Brendon "seriously menacing."
"What this series does really well is take an ordinary high school situation (bullies and gangs) and move it to a higher, more horrible, and more absurd level (hyena transpossession).
Club gave "The Pack" a grade of B, writing that "the storytelling in this episode is engaging and a few of the scenes genuinely creepy", though its central metaphor was not as developed as "Teacher's Pet".
[7] A review from the BBC described it as "a highly inventive episode with an unusual premise, albeit one that is somewhat difficult to believe."
The review praised Xander actor Nicholas Brendon, but felt that "the supernatural elements are clumsily handled" and called the ending "rushed and muddled.
"It’s a pretty heavy-handed metaphor about hormonal teenagers, but honestly, it plays out in such a silly, stupid way that it’s hard to not love this episode.