Siblings Ellie (Ricci) and Jimmy (Eisenberg) are driving back to their home near the Hollywood hills one night when they collide with another vehicle, sending it careening into the forest below. While attempting to help the other driver, a young woman named Becky Morton (Shannon Elizabeth), get out of her car, they are suddenly attacked by a large beast emerging from the shadows. The creature drags Becky into the forest after biting and scratching Ellie and Jimmy. When paramedics arrive and ask the siblings what kind of animal attacked them, Jimmy can only respond that it looked like a "wolf the size of a man".
Soon after, they start noticing changes within themselves. They're getting stronger. Their reflexes are faster. They seem to be more attractive to members of the opposite sex... and the scent of blood has a powerful effect on them. Jimmy is quick to realize what's going on: they're becoming werewolves. His excitement is quickly overshadowed, however, when they learn that more and more young women are being violently attacked. Ellie and Jimmy realize that the werewolf that cursed them is stalking the streets of L.A., and with the first full moon since their attack quickly approaching, they may very well be its next prey of choice.
Notable for having its werewolf designed by Rick Baker.
This film contains examples of:
- Action Survivor: Jenny eludes the werewolf for a while by hiding under a car and then on a running board while hanging on to the door handle and rearview mirror once it starts looking under the cars. She ditches her high heels and uses her remote key to set off a car alarm to distract the monster, allowing her to flee to an elevator. Once the werewolf tries to get into the elevator, she immediately goes for the emergency phone, then tries to climb to the opening in the elevator roof.
- Armoured Closet Gay: Jerk Jock Bo who is secretly crushing on Jimmy.
- The Beard: It looks like Brooke was this to Bo.
- Beta Couple: Jimmy and Brooke, to Ellie and Jake.
- Big Bad: Jake is the original werewolf.
- "Blackmail" Is Such an Ugly Word: Joanie doesn't wanna kill Ellie - just to rip her to shreds and watch her choke on her own blood. And maybe eat her.
- Bloody Hilarious: Becky's death scene in the beginning of the film can qualify.
- Boom, Headshot!: The police kill Joanie this way as blowing her brains suffices as decapitation.
- Buxom Is Better: Discussed by Ellie and Jimmy.Ellie: Shouldn't the werewolf be off terrorising helpless maidens?Jimmy: Maybe it's a hip werewolf. It likes its maidens with the perfectly implanted breast.
- Can't Get Away with Nuthin': Played for Laughs with this little line...Jake: How did this happen?Joannie: I guess there's no such thing as safe sex with a werewolf.
- Defeat Equals Explosion: When the werewolf who infected all the other major characters dies, he inexplicably explodes in a burst of greenish energy.
- Expository Hairstyle Change: To demonstrate his werewolf sexual aura, Jimmy gels his hair into a trendy style.
- FaceHeel Revolving Door: Jake is revealed as the werewolf, but Joannie is the one killing people. But then it turns out Jake is evil too.
- Flipping the Bird: Not often you see a werewolf doing this.
- Hate Sink: A contrast to the more entertaining Joanie, despite starting out as a loving boyfriend, Jake Taylor loses such qualities upon being revealed to be the Alpha Werewolf who bit Ellie and Jimmy. This may also imply he might have killed his ex girlfriend Becky, and possibly Jenny. Jake is a womanizer seeking for the perfect girl to be his life mate, and upon revealing his true colors, becomes possessive towards Ellie and trying to kill her brother. Throughout this, he belittles Ellie for being "weak", mocks her over her failures in life and her parents death.
- I Didn't Mean to Turn You On: The lycanthropic curse causes those around them to be extremely attracted to the one who is cursed. Ellie especially notices this with a male assistant of hers, and Jimmy is surprised when it happens to the male jock Bo... neither of which the siblings had any intention in pursuing.
- It's a Small Net After All: Jimmy finds all the information he needs on werewolves through one internet search.
- Jerk Jock: Bo (played by Milo Ventimiglia), the captain of the high school wrestling team and Jimmy's rival for Brooke's affection. He's gay and actually not so bad.
- Just Hit Him: How does a werewolf with sharp claws and teeth fight? By throwing people around apparently. Unless said werewolf is trying to AVOID making more of their kind.
- Letting Her Hair Down: Ellie does this as demonstration of the werewolf sexual aura. Joannie comments on this.
- Mr. Exposition: Jimmy, thanks to a few handy books about werewolves.
- Off with His Head!: To kill a werewolf you have to separate the head from the heart - and this is the easiest way to do so.
- Our Werewolves Are Different: Werewolves have a powerful sexual allure to members of the opposite sex. And sometimes the same sex. In addition, while silver is painful to lycanthropes, it cannot kill them.
- Plot Hole: A small but glaring one. With the revelation that Jake is the werewolf who bit Ellie and Jimmy, this contradicts the previous revelation that Joanie is the werewolf killing people throughout the movie. This is because the werewolf who bit Ellie and Jimmy is the same one who kills Becky at the beginning of the film. Are they trying to imply that Jake was also the one who killed Becky (and possibly Jenny) as well? Is this some sort of Double Red Herring? The movie doesn't really answer this after the revelation that Jake is the Big Bad.
- Police Are Useless: Suprisingly averted when they gun down Joanie and successfully kill her with a headshot.
- Really Gets Around: Jake. By the time the film's over, we've counted four women he's been with in the last month or so.
- Red Herring: Kyle, briefly. And very poorly done too.
- Sacrificial Lamb: Becky is developed enough so that her death proves meaningful.
- Shout-Out: The design of the night club owned by Ellie's boyfriend, Jake (played by Joshua Jackson), is one big shout out to classic horror movies. It is lined from wall to wall with supposed memoribilia from the movie sets, including the silver-tipped cane from the original The Wolf Man (1941).
- Significant Wardrobe Shift: Ellie switches from black pantsuits to more colourful and feminine office wear when she gains her sexual aura as a werewolf.
- Werewolf Refugee: Ellie and Jimmy. While Ellie falls under the "What Have I Become?" category, Jimmy leans more towards a "Friendly Neighborhood Werewolf" type.
- What Measure Is a Non-Cute?: After Jimmy and Ellie explain that they only ran Becky off the road because they hit an animal, she concernedly asks if it was a dog.
- Wrestler in All of Us: After Jimmy figures out what he's becoming, he uses his skills to try out for the high school wrestling team and wins using various obvious pro-wrestling moves, including a straight-legged backwards suplex complete with a 5 second "pause" (and a pre-suplex one-liner) before dropping his opponent.
- Yandere: Joannie, a werewolf version.
- You Are What You Hate: Bo is gay, and becomes attracted to Jimmy. Surprisingly enough, this does not end in either dying.