As a Moments subpage, all spoilers are unmarked as per policy. You Have Been Warned.
- The first moments are subtly creepy, as they're shown from Billy's view, where he shuffles around the sorority, then climbs in through an open window and spies on the girls from the attic. In most horror movies, we never know where the killer is at any given time. Here, we always know that he's just upstairs.
- Every single time Jess is left alone in the house it creates a massive sense of dread, because we know the killer is already inside, and could strike at any moment.
- Just to really hammer home how unsafe the characters really are, at one point when Jess is talking to the police over the phone, Billy's shadow can be seen moving in the background.
- Every single one of those damn phone calls. Unlike later slasher movie icons like Michael Myers and Jason Voorhees, Billy isn't some silent, emotionless entity. Rather, he's a snarling, sniveling, cackling creep who frequently alternates between voices (possibly implying some form of schizophrenia), breaks down into sobbing fits, and makes all measure of obscene sexual threats.
- The first phone call is arguably the worst. After squeaking like a pig and screaming sexual threats, Barb casually makes fun of him and insults him right back. In a calm tone, Billy replies "I'm going to kill you", then hangs up.
- As per the Alternative Character Interpretation on the YMMV page, we also know absolutely nothing about the guy. No backstory, no motivation, just who the hell Agnes is, nothing. Hell, we don't even see what he looks like; instead we just get heavily shadowed glimpses of him.
- The allusions Billy keeps making to Agnes is just enough for someone to deduce that something terrible happened to her at Billy's hands. When Billy does his imitation acts, he screams lines like "You left Billy alone with Agnes?!", "Where's Agnes?", and "Dirty Billy!", and later on during Barb's murder he says "Don't tell anyone what we did, Agnes.". The implication being that, whatever happened, it means that Billy's been a dangerous person for potentially years.
- A few throw away lines early in the film suggests that Billy's been active long before the events of the movie, since the sorority girls are not only familiar with his threats and obscene rants (to the point where they've given him the nickname of "The Moaner"), and when one of the sorority girls mentions someone in town had gotten raped two weeks prior. It gives off the impression of a psychopath gradually escalating his criminal behavior until an all out massacre occurs.
- Special mention goes to when he practically wails into the phone, "JUST LIKE HAVING A WART REMOVED!" In-Universe, it's a Wham Line, because Jess thinks it's Peter, but in general, it's just delivered in such a disturbing manner.
- At one point in the film a mother goes to the police to tell them that her thirteen year old daughter has been missing for hours. A search party is sent out to find the girl, only to find her murdered. We're never shown the corpse, but the various reactions of the characters to seeing it tell us that whatever happened was gruesome.
- Claire's murder. Billy lures her into a closet, and once she's in striking distance Billy wraps a plastic bag over her head to strangle her with, while an incredibly loud sound of Claire struggling to breathe is played.
- Every single time the movie cuts to Clare's increasingly rotted corpse sitting in the rocking chair with a bag over her face (pictured above). It just serves to remind us that, no matter how hard the protagonists look for her, they're never going to see Clare alive again. The fact no one ever discovers her body just makes it worse.
- Even though he isn't the real killer, Peter is still an unnerving character. Like Billy, he's got his own Alternative Character Interpretation entry, and is a pretty realistic depiction of an abusive partner - controlling, manipulative, callous, and surprisingly violent, casually destroying a piano after a bad recital. It's not at all surprising that Jess believes him to be the killer, because in any other slasher movie, he probably would be.
- Barb being stabbed to death with a figurine. The scene is made even more disturbing by being intercut with shots of Christmas caroling children.
- Ms. Mac being stabbed and hanged with a crane hook. What makes it worse is that Billy waits for her to see Claire's corpse, then waits for her to turn around and face him, before he releases the hook and kills her. He wanted her to be afraid before he killed her.
- One of the most Paranoia Fuel-inducing lines in horror: "The calls are coming from the house!"
- When Jess hears this line, she shouts upstairs for Phill and Barb, becoming increasingly frantic when they don't answer. At this point, they're already dead, and Jess is alone in the house.
- To emphasize this point, far prior to this the Detectives had posted an officer outside the house to monitor it and to make sure nothing suspicious goes on. When they try to reach him, the camera pans up to reveal his throat's been cut open. There is no-one for Jess to turn to and the authorities are too far to reach her in time.
- When Jess hears this line, she shouts upstairs for Phill and Barb, becoming increasingly frantic when they don't answer. At this point, they're already dead, and Jess is alone in the house.
- The ending. After the cops have left and Jess is left to lie in bed, the camera pans throughout the house and stops below the attic, which slowly opens with a creak. We then cut to Mrs Mac and Clare's bodies in the attic.
- And during the credits, the phone begins to ring. The killer is still in the house...
