August 24, 2001 | How awful can a movie be without actually leaving a stain on the screen? Bubble Boy skirts perilously close to the outer limits of what can be unspooled at a multiplex without making the worst kind of lasting impression. Indeed, under normal circumstance, it would be a strong candidate for Worst Movie of 2001. But Freddy Got Fingered already has a mortal lock on that title, so this fifth-rate farce will have to settle for second-place dishonors.

I don't think you want to read much about Bubble Boy, and I know I don't want to write much about it, but try to imagine something Peter and Bobby Farrelly might make if they had no talent whatsoever, and you'll have some idea what to expect. Jake Gyllenhaal reneges on the promise he displayed in October Sky with his charm-free performance here as Jimmy Livingston, a 17-year-old doofus who has spent most of his life inside a plastic dome in an upstairs bedroom of his suburban California family home. He's allegedly ensconced in this germ-free environment because of his life-threatening immune deficiency. But it seems much more likely, given the way Gyllenhaal plays him, that the boy simply is too stupid to be set loose on his own in the world.

Swoosie Kurtz embarrasses herself, and us, by playing Jimmy's oppressively protective mother, a horrendous and hypocritical born-again zealot who rails against Jews and minorities, bakes cookies in the shape of crucifixes, and rewrites bedtime stories to repeatedly reinforce a cautionary message: Don't ever leave home and, more important, always listen to your mother.

Despite this indoctrination, Jimmy falls for Chloe (Marley Shelton), the girl next door - or, as his mom calls her, "that slut next door" - and Chloe in turn is charmed by, among other things, his budding talents as a rock guitarist. Now you might well wonder why Jimmy's unforgivingly uptight mom would buy him a guitar in the first place, much less permit him to play rock music, but never mind: If you stopped to think about every logical inconsistency in Bubble Boy, you'd never get through this benighted garbage. Besides, even though it clocks in at less than 85 minutes, the movie seems quite long enough already, thank you very much.

Jimmy bursts out of his bubble only after Chloe announces plans to marry a sleazoid musician (Dave Sheridan, behaving like the third-place runner-up in a Jim Carrey impersonator contest) in a Niagara Falls ceremony. Following his heart, Jimmy jury-rigs an airtight bubble outfit to keep himself healthy and germ-free, then hits the road. Along the way, he encounters a surly Latino biker, an excitable Indian vendor of curry and ice cream, a doomsday cult of "Up With People"-style singers (led by paperback-cover hunk Fabio, who acts as though he gets the joke), a group of sideshow freaks "owned" by a malignant midget (Verne Troyer, the Mini-Me of Austin Powers infamy) and a gaggle of shrieking Asians who bet big money on mud-wrestling matches.

The makers of Bubble Boy evidently subscribe to the notion that you can get by with any kind of blatantly offensive ethnic joke or religious slur as long as you're brazenly upfront and comically overstated in your political incorrectness. It is, at best, a dubious premise. At worst - that is, all throughout this movie - the anti-Semitic punchlines, the ethnic stereotyping, the mockery of the physically challenged and all the other cheap, nasty, mean-spirited jokes concocted by director Blair Hayes and screenwriters Cinco Paul and Ken Daurio fail miserably because they lack the saving grace of actually being funny.

Typical of the movie's anything-for-a-laugh shamelessness is a last-minute revelation. (Spoiler alert: I'm about to reveal the "surprise" ending.) Jimmy's mother finally fesses up, and reveals that Jimmy hasn't been immune-deficient since he was four years old. She kept him inside the bubble only because she never wanted to lose him. Which, when you think about it, indicates that she isn't just a smothering, hypocritical harpy, she's also a borderline-psychotic monster. But, then again, I warned you against thinking too much about anything in this movie, didn't I?