'SPIDER': A MIND IS A DANGEROUS THING TO ENTER.

Byline: Bob Strauss Film Critic

RALPH FIENNES snorts, yelps, mumbles and babbles his way through ``Spider'' so expertly (and excessively) that you only want to get away from him. Now.

While this is probably not the way to spread positive word-of-mouth about David Cronenberg's latest test of audience endurance, it is as imaginative and impressive a piece of work as any the always-extreme actor has ever recorded (``Maid in Manhattan'' excepted, of course).

And Fiennes' isn't the only brilliant performance in this harsh, austere movie that goes many steps beyond what we think of when we hear the term psychodrama. Miranda Richardson creates one of Cronenberg's most memorable shape-shifters as Dennis ``Spider'' Cleg's mother, a woman both enshrined and demonized in the demented man's collapsing spook-house memory. Also remarkable is 10-year-old newcomer Bradley Hall, who with great care and the utmost bravery plays the child Spider as he's just shifting into the tremulous wreck of Fiennes' creation.

And though they have less demanded of them, Gabriel Byrne, Lynn Redgrave and John Neville play their parts with expert precision in what, by nature, is that most exclusive of chamber dramas: a story that unfolds within the confines of somebody's head.

It is not a nice place to visit. Institutionalized for decades, Spider (nicknamed that for the elaborate string webs he liked to tie about his boyhood bedroom) shuffles his way into a dreary London halfway house run by the intimidating Mrs. Wilkinson (Redgrave). Unfortunately, the peeling, brown-water row house is in his old neighborhood; if Spider hadn't been thinking about The Big Event during his years of full incarceration, wandering around the grimy streets brings the memories flooding back immediately.

Cronenberg, who never met a visual mind trick he didn't like (see ``Dead Ringers,'' ``Videodrome,'' ``M. Butterfly,'' ``Naked Lunch'' ... heck, the whole works), provides some kind of plan to the complicated flashback structure that ensues. In many scenes we watch a silent, haunted Fiennes watching the Hall version of himself interacting with Mum and Dad (Byrne). But other sequences set 30 or whatever years before the film's present don't include the Fiennes ghost. Are they the ones that show what really happened or Spider's fevered imaginings? It's not always easy to suss out, especially when - whether the lead actor is dithering or just pregnantly staring on screen - your eyes are more inclined toward locating the auditorium exit signs.

The screenplay was written by Patrick McGrath, based on his novel of the same name. McGrath's father was medical superintendent at a British hospital for the criminally insane, and many of his best works (``Asylum'' is another one) examine such conditions with the unflinching candor and sympathy only long observation - filtered, perhaps, through a child's accepting and simultaneously extravagant sensibility - can nurture.

Cronenberg and Fiennes have transferred that perception to the screen as faithfully as any writer could hope they would. Whomever else this could possibly make happy remains to be seen.

SPIDER - Three stars

(R: violence, nudity, sex, language)

Starring: Ralph Fiennes, Miranda Richardson, Bradley Hall, Gabriel Byrne, Lynn Redgrave, John Neville.

Director: David Cronenberg.

Running time: 1 hr. 38 min.

Playing: Sunset 5, West Hollywood.

In a nutshell: Uncompromising inquiry into the mind of a homicidal schizophrenic. Fiennes and Richardson give expert performances.