I really can't say to much about the plot of this movie other than it has none. It took them five movies to get to the enginer, and only 60 pages in the book. Ok well let me really think about this for a sec.
This movie sucked and it really did no justice to the series. The whole storyline just doen't flow well either.
The Cenobite effects suck. The dead hooker did look good though (special effect wise). This is a round, and round mind fuck movie, and when you finally get to the end the only thing it will leave you feeling is disapointed. It kinda like Groundhog Day with Cenobites and no Bill Murray. Except I'd rather watch Groundhog Day.
Well now you have my two cents about that, and hopefully I can help you from wasting your money. But if you still want to see it, let me tell you now don't expect much.