Taking a somewhat different approach to the Hellraiser mythos, it seems someone has turned the legend of Pinhead and his Cenobites into a "World of Warcraft" style online roleplaying game.
Anyway, a group of friends (one of which being a then unknown Henry Cavill) who are heavily into this online fantasy thing are thrilled when they win tickets to an exclusive Hellraiser themed party, which happens to be taking place at an old Asylum, that was supposedly designed by Philip LeMerchant (the guy who invented Pinhead's lament configuration box in Part 4).
The group are welcomed by the party's host (played by Horror B-movie veteran Lance Henricksen), who's a huge collector of LeMerchant's works, and are given a grand tour of the building, where they're plied with drinks and given special mobile phones so that they can communicate with the other party goers.
But as they start to get into the party spirit, the group soon finds things aren't what they appear to be. One of them finds an apparent torture room and is brutally murdered by the host, another gets stuck in the basement and finds that Pinhead and his cenobites are apparently all too real, whilst a couple of the others seem to find they're invisible. One things for certain, either someone spiked the party punch, or the host has some connection to Pinhead and is turning the festivities into one "hell" of a party.
Directed again by Rick Bota, this is actually one of the better of the later Hellraiser sequels (though that's not saying much) which, as with the last few films, looks like it was adapted from an unrelated script. There are a few scenes in the film that may seem out of place, such as Pinhead appearing to use a meat cleaver to kill one of his victims, but if you watch right to the end the reasons for this become apparent.
So to sum up, not bad, but not brilliant. Lance Henricksen's appearance was probably the best thing about this, even though I feel he is terribly wasted in these sort of films and it was kind of interesting seeing a young Henry Cavill, prior to playing Superman. There's also a neat twist in the ending as to what happens to the host (which I won't spoil), though there's another twist after that which didn't really make much sense. As with the last few films, really one for die-hard fans of the series only.