Plot:
It was quiet in the house, not a creature was stirring not even a mouse. Okay you get the point. After a college day, Kelly Bradford and her sisters Lauren and Melissa, along with housemother Mrs. Shepard, host a party. The party includes of Megan, Riley, Eddie, Gary, Jane, Joe, Sarah, Jackie, Axel, Julie, Ellie, Patricia, Kristine, Kevin, Rose, Andrea, Diana, Tiana, Theresa, Penny, Selena, Andre, Serena, Rebecca, Olivia, and Jenny.
The party goes great. The snow storm makes the phone line not work however, so Serena can't call her mom to let her know she's at a party.
The power suddenly goes off in the dining room. Olivia, who is a technician, brings Jenny and Rebecca so they can go see what's up with the power. Jenny gets pulled into the crawlspace while she's out of there after fixing the power and is stabbed twice in the back. Olivia and Rebecca hear blood splatter and Olivia is stabbed in the leg and gutted. Rebecca gasps and backs into the fence as the killer slams an axe into her head.
Kelly gets concerned when none of the three return, and sends Andre to check on them. He finds them standing at a fence, but before he can realize they are dead, the killer bags him and slams his face into an exterior wall.
Everyone gets partying again. Serena drinks too much and pukes, so Kelly helps her get ready for bed. Everyone else leaves to go party outside, leaving Selena to take care of Serena. While Selena goes downstairs to get candles ready, Serena is dozed off. She feels something in her blanket, almost like a human hand, and it's touching the blanket. Serena takes a glass unicorn from Lauren's bedside and when it gets close to her, she stabs at the hand, but nothing. Then, the killer chokes her and grabs the glass unicorn, jabbing it into her head. Selena is then attacked by the same killer and is bagged. She escapes, but is soon knocked to the ground, pinned down, and cut open.
Penny and Theresa, along with Kelly, Lauren, and Mrs. Shepard leave to go to the mall. They leave everyone else behind. Diana and Tiana go to the basement and turn the hall only for Tiana to get bludgeoned and Diana to get stabbed. Andrea goes to the bathroom to take a shower and after seeing a shadow, is attacked and has her head crushed against the wall of the shower. Rose sees the corpse but is knocked into the tub and drowned.
Meanwhile at the mall, Penny and Theresa are attacked outside. Penny has her head sliced off and her body is hid in the woods and Theresa has her throat slit and her head dunked into the lake in the woods.
Kevin takes his clothes to the laundry, puts them in and puts them back on. He hears banging, but the killer slams him into the wall and guts him.
Kelly, Mrs. Shepard and Lauren let the others leave and so nobody is there except them, Kristine, Melissa, Patricia, Ellie, Jackie, Sarah, and Jane. Kristine goes to the bathroom and finds Kevin' corpse. She tries to call 911 but the killer grabs her and snaps her neck.
Julie and Riley also return to the sorority house to stay there for the weekend. Patricia also pukes and Ellie takes care of her in Laurens bedroom. Ellie goes to the bathroom and washes her hands while a second killer appears with the first killer in Patricia's room. The first one hides in the mattress while the second one knifes Patricia in the face. Ellie returns and finds Patricia's body. Before she can scream, the other killer guts her viciously.
Melissa is taking a shower in order to be able to date Tom but is attacked and her neck is slashed open. Jackie is putting herself to bed when she hears Melissa gurgling. She thinks nothing of it and goes back to sleep.
People want to leave but Lauren and Sarah don't want to leave Jackie, Jane refuses to not have Ella and Patricia in the house alone, and Kelly says they should be stuck in groups so Julie and Mrs. Shepard go to the car to leave, but when Julie realizes Mrs. Shepard left her purse in the house, Mrs. Shepard leaves. However, the killer stabs Julie twice and Mrs. Shepard backs into the fence and an icicle falls into her gut.
Riley goes to the bathroom and is attacked by the killer. She escapes, but Kelly mistakes her for another killer and decapitates her. Everyone is confused when the car doesn't leave and is surprised when they find out Kelly accidently killed Riley.
Axel and Eddie arrive so Eddie can meet with his girlfriend Jackie and Axel can meet with his girlfriend Jane. Gary also arrives to meet with Lauren and so does Joe so he can talk to Sarah.
Then Billy Lenz is revealed to be the killer as he is calling Kelly and kills everyone else. Axel goes upstairs to get drinks and is stabbed in the neck. Jackie goes outside but she is attacked and impaled on a tree branch. Sarah and Joe are finished with making food and begin to talk. Sarah is stabbed in the mouth and Joe escapes but is stabbed in the back. Gary is cut open and then Jane is stabbed in the neck also.
Lauren and Eddie find the bodies of Jane and Sarah and Kelly arrives just as Billy stabs Eddie and chokes him to death. Lauren and Kelly then pin Billy down and tear his eyes out. The movie ends.