The Pack is a highly inventive episode with an unusual premise, albeit one that is somewhat difficult to believe. The supernatural elements are clumsily handled, and the Primals' ability to transfer their spirits into their human hosts are not adequately explained. The ending seems rushed and muddled too.
Nevertheless, Nicholas Brendon shines as the possessed Xander, exuding menace and unease in every scene he's in. The scenes where he snubs Willow and attacks Buffy are genuinely upsetting.
It would have been nice if the story could have been stretched to allow scenes where the human hosts became even more animalistic but this would probably have necessitated elaborate - and expensive - make-up, and might have earned the episode an X-certificate. As it is, it comes pretty close to the knuckle anyway, with scenes that must have sent the censors scurrying for their rulebooks.
The cannibalism element is not gratuitously exploited but it seems likely that viewers will be rather more saddened by the death of Herbert the pig than the demise of Principal Flutie.
