WITHNAIL AND I" is about, among many things, cabin fever, venting spleen, and never doing the dishes. Bruce Robinson creates an entertaining mix of farce and existential gloom in the "No Exit" bowels of England's capital. Although his tale of two Londoners going looney never quite coheres, the humor is so sardonically amusing that you enjoy it anyway.

The film marks Robinson's directing debut. The writer and former actor played the object of Isabelle Adjani's obsession in "The Story of Adele H," and wrote the screenplay for "The Killing Fields." Ironically, Robinson's direction saves him from his own plot structure. The characters move in pointless dramatic circles, but they are amusing, thoroughly watchable beings.

It's 1969 (or at least that's what everyone in the movie keeps saying). Two jobless actors, Withnail and Marwood, are stuck in their Camden flat without food, drink, heat or work -- the average London existence. Withnail curses and moans. Marwood anxiously tries to comfort him. They seem to have much the same lot as writers Joe Orton and Kenneth Halliwell in Stephen Frears' "Prick Up Your Ears." Except these guys are less talented, more depressed and they don't meet boys in public restrooms. And while Robinson doesn't achieve the sophisticated interaction of Frears' Orton-Halliwell affair, he does paint his characters colorfully.

Withnail (Richard E. Grant), handsome, eyes bloodshot, has been awake for 60 hours. He's angry and full of himself. "I'm good looking," he says. "Why can't I get on television? I'm going to crack." Though he's also prone to lying and stealing to get what he wants, Withnail is somehow likable -- perhaps because of his valiant, bungled quest for dignity.

Marwood (Paul McGann), whose existential panic is more subdued but is there nevertheless, persuades Withnail to take off for some "harmony and fresh air." They take their rusted Rolls Royce to a country retreat in Penrith, owned by Withnail's Uncle Monty (Richard Griffiths), who gives new meaning to the word "eccentric." He's a former actor, tubby, well-educated and financially comfortable. Emotionally, however, he's all wet. He gets pointlessly upset over his cat, swims sentimentally in old-boy memories of Oxford -- and the liquor-soused gent has the unrequited hots for Marwood. (Withnail has, of course, conned him into believing Marwood will sleep with him.)

Penrith may be full of fresh air, but it's fresh out of harmony. Withnail and Marwood, city slickers to the core, learn that their first meal is a chicken they're obliged to kill. There's no firewood. It's always raining. The locals' hostility is comparable to the folks in Sam Peckinpah's "Straw Dogs." And then randy Uncle Monty pays his guests a surprise visit . . .

The plot in "Withnail" is a series of collisions among miserable people. Robinson lets them wallow in their private hells, but that wallowing is both alarming and hilarious. After watching this, you will think twice about taking up acting. And you may never visit Penrith.

WITHNAIL AND I (R) -- At the Key.