Determined, I suppose, to start like a house afire, the new supernatural thriller "Firestarter," now at area theaters, opens on a note of false urgency that leaves the exposition in an instant state of hysteric dishevelment. Since the filmmakers never stage a recovery, this state of affairs eventually becomes permanent.

The latest would-be terrifying shambles abstracted from the endlessly boil- ing literary pot of Stephen King, "Firestarter" also litters the screen with a higher percentage of excruciating performances than any stinker in recent memory. The ostensible scourge of the story, Drew Barrymore as a little girl called Charlie who possesses awesome incendiary powers, doesn't leave nearly as much credible devastation in her wake as director Mark L. Lester. Indeed, Miss Barrymore, degenerating into a puffy-faced whiner a mere two years after her beguiling debut as the kid sister in "E.T.," must be numbered among the hapless victims of Lester's evident knack for subjecting actors to ridicule.

David Keith, cast as Charlie's desperate father, a psychic of lesser magnitude, tries without success to shield her from being captured and exploited as a potential superweapon by a sinister government agency (suggestively known as The Shop, which should give you a fair idea of the general level of cleverness). He must spend a preposterous amount of time with his fingers pressed to throbbing temples, struggling to disarm pursuers with thought projection despite the toll it exacts in migraines and nosebleeds. It's the first time I've seen Keith give a bad performance, but under the circumstances, he doesn't have much alternative.

Lester's sucker list goes on to include George C. Scott, Freddie Jones, Art Carney and Moses Gunn, respectively cast as a ruthless government assassin, a frantic scientist, a friendly yokel and a pompous scientist. Assuming they gave the director what he wanted, his demands were hilariously primitive.

For some unaccountable reason that bad-role specialist Martin Sheen contrives to finesse his dubious assignment as Scott's crony, even while walking around under a wavy pompadour that seems to add a fleecily ludicrous dimension to his head. From "Gandhi" through "The Dead Zone," Sheen could be counted on to belabor the obvious, especially if the obvious had ideological logs to roll. All of a sudden he turns up acting enjoyably foxy in this patently worthless vehicle, so go figure it.

Scott, perhaps camping it up in deadpan tandem, has affected a flowing gray mane that combines with his crumbling monumental visage to suggest a corrupted old Indian chief. His wicked character is supposed to have a touch of the mystic--he likes to kill with a karate chop across the face in order to groove on the shock in victims' eyes at the moment of death. Just the sort of psychology we're anxious to see George C. Scott illuminate at this stage of a distinguished career. Part of the time, he also puts on a Rooster Cogburn eye patch. The motive for this touch remains a mystery in or out of context.

Even before it begins laying waste to the reputations of cast members, "Firestarter" is promptly exposed as a derivative embarrassment of a conception. What could be better calculated to illustrate King's recent decline than a "new" thriller whose devices have been poorly cribbed and patched together from "Carrie" and "The Fury"? As a matter of fact, "Charlie's Fiery Fury" would be a catchier bad title than "Firestarter."

The heroine wreaks havoc by going into a heavy-breathing trance that produces spontaneous combustion, either igniting the objects of her concentrated displeasure or forming fireballs that take off like guided missiles. The only persuasive illusion is that certain stuntmen are being engulfed in flames in the line of duty, a situation that seems more compelling than the little heroine's alleged need to defend herself by launching a special-effects holocaust. Drew Barrymore is perhaps too young to be entrusted with the sort of pantomime that Sissy Spacek and Amy Irving could make electrifying; at any rate, Lester is incapable of coaxing a persuasive approximation of fury out of her.

A curiously photogenic side-effect of Charlie's feverish brain activity is to create updrafts that lift her hair parallel to the ground, but this windblown phenomenon gives her an aura more angelic than diabolical. The evidence suggests that Lester might be a worldbeater if he confined himself to lyrical shampoo commercials.