Teen misfits Gary (Anthony Michael Hall) and Wyatt (Ilan Mitchell-Smith) design their ideal woman on a computer, and a freak electrical accident brings her to life in the form of the lovely, superhuman Lisa (Kelly LeBrock). She outfits Gary and Wyatt in cool clothes, surprises them with a Porsche and helps them stand up to jerks Ian (Robert Downey Jr.) and Max (Robert Rusler). But, all the while, the boys must hide Lisa's existence from Chet (Bill Paxton), Wyatt's nightmare of a big brother.