As one reviewer said, it's The Breakfast Club in the House of 1000 Corpses...and I'd add Come Back To The Five And Dime, Jimmy Dean.
Bernadette, a lovely psychotic psychologist, plans a party murder mystery party for her friends...and then drugs them so they can't move. From there, she exposes their lies and hypocrisies. Sure, the fact that she's engaged in deception to know all that she knows and has her own hypocrisies doesn't make sense...that's why she's psychotic. In the course of the night, she shows the hidden videos of the "friends" cheating on each other, raping each other and spying on each other, while keeping their secrets. Throw in some mushrooms and general trippiness and what's not to like?
The rock solid script takes you through the various sins with some excellent group dynamics and ensemble acting. Towards the end, Jules (the blond bombshell who's tripping) goes into a full blown hallucination which throws out an even more unsettling vibe with a gasp-inducing consequence.
Everyone is spot on in their roles. Bernadette plays her insanity with a subtleness and restraint that could have thrown the movie off the rails. This provides the perfect contrast in the rare moments when she does flip out. Jules, too, shines in her role and brings depth to her party-girl persona. When I first saw her, I thought she was too pretty bring off the role but she fearlessly takes on the drug trip aspect and sells it brilliantly.
All in all, it starts up quick and maintains its pace providing an amazing ride!