"ORPHANS" OPENS humorously enough: A mugged yuppie starts whining, convinced a minor knife wound on his arm will kill him. But just when you think you're in for a sardonic, funny ride, Alan J. Pakula's film changes tone. It leaves the cinematic outdoors, enters the rundown home of two orphans, and becomes a stagey house of bathos.

The orphans, brothers Treat (Matthew Modine) and Phillip (Kevin Anderson), live in a house of empty tuna cans, soiled mattresses and megajunk in Newark. They're penniless and overwrought. Treat (the one who mugged the yuppie) tends to throttle, kick or knife people when he's upset. And Phillip, of subterranean self-esteem, has stayed indoors ever since his big bro' told him the outside air will suffocate him.

A typical day: Treat goes out to mug and phobic Phillip stays at home playing imaginary basketball, trying to teach himself to read or just knocking things over. If you close your eyes, "Orphans" sounds something like this: Banga-BANGA. Kerdangle, clang-BING!! Pause. Ke-DANGHH!!

Then, why have two over-actors when you can have three? Adding expansive class to adolescent spleen, Albert Finney enters, stage right. As Harold, a money-laden and benevolent gangster, he plays that British drunken-prince shtick perfected by Peter O'Toole, Richard Burton . . . and Albert Finney. It's a simple formula: slur grandly, roll your eyes and tell jaded anecdotes. Never misses.

It misses. Rolling Shakespearean eyes and breathing heavily, Harold tells of his bad ol' days in a Chicago boys' home -- which is why he loves these two "dead-end kids." And proclaiming himself the boys' Big Daddy, he pumps money into their home and wardrobe. He subjugates excitable Treat into a dandyish bodyguard who must make daily trips to a Manhattan safe. And with a few paternal shoulder squeezes, he turns Phillip -- a sorry boy who seems to need years of counseling and probably prescription medication -- to A New Phillip, who opens the window and lets the rain fall on him (baptism, see). Who tears around the wasteland around the house in circles. Who learns to use a map. Who talks higher education . . .

The only thing left at this point is the ultimate theatric: the deathbed scene. But you won't read the details here. It's anybody's guess why Pakula chose Lyle Kessler's 1983 play -- which, if it has any relationship to Kessler's own adaptation, is nothing but amateurish gallery-playing. "Orphans" is much ado about nothing in a house that inexplicably gets free electricity.

ORPHANS (R) -- At K/B theaters.