Jennifer (Alicia Silverstone) is a lovely teen who has been hired to baby-sit the kids of Harry Tucker (J.T. Walsh) and his wife, Dolly (Lee Garlington). The Tuckers go to a party and proceed to get inebriated, with Mr. Tucker fantasizing about his beautiful baby sitter. Meanwhile, Jack (Jeremy London), her boyfriend, and Mark (Nicky Katt), another guy interested in her, decide to spy on Jennifer at the Tucker house, with each young man also fixated on her.

The mother of the family for which Michelle baby-sits dies unexpectedly. Michelle is asked to take over looking after the children and is gradually "seduced" by the father. When suspicions arise that the mother had been murdered (and had been having an affair), Michelle unknowingly becomes enveloped in a web of lies until she herself is suspected. Gradually she realises all is not as it seems...

After discovering an urban legend of a demented serial killer, who has nothing but a carved "smiley" on his face, a mentally fragile teenager must figure out if she is going insane - or if she could be the next victim.