UPON FIRST GLANCE at the synopsis of Jesus' Son, one might wonder, "Do we really need another tale of hopped-up hijinks set amidst the unwashed yet funky classes in a bygone pre-Reagan era, featuring a cast of indie film all-stars, a series of darkly funny misadventures, and a deftly chosen soundtrack of the period?"

Then again, how can a movie whose main character is known only as Fuckhead be all that bad?

"FH," as he is demurely referred to in the credits, occupies space in Iowa City circa 1971. His existence takes shape upon meeting Michelle, a seemingly kindred spirit who turns him on to the joys of shooting up. The pair experience the fairly predictable ups and downs of the junkie life, and Fuckhead eventually learns a thing or two about keeping it real. That's pretty much it.

As Fuckhead, Billy Crudup, looking like Vincent Gallo on a good day, gets the chance to dress down and sport brazenly unkempt hair that he missed in his last '70s role, as doomed Oregon track star Steve Prefontaine. He's convincingly dim, but with a human core in there somewhere that keeps us rooting for the little punk. Samantha Morton exudes talent and charm as Michelle, inhabiting her Midwestern accent flawlessly (you'd never guess she was a Brit). Michelle's lack of inhibition mark quite the contrast from her Oscar-nominated turn as the shy mute in Sweet and Lowdown.

Canadian-born director Alison Maclean, whose only previous feature was the memorable, if puzzling, 1993 film The Crush, has taken the loosely linked short stories of Denis Johnson's acclaimed collection and kneaded them into a shaggy, narrative arc. As the story's spine (as they say), Maclean and the trio of screenwriters have shoehorned the relationship between FH and Michelle into a more prominent place than it probably deserves.

Fortunately, the diversions FH encounters on his long, strange, trip are thoroughly memorable. Denis Leary shows up as Wayne, an alcoholic barfly with some pathetic ideas on how to make a quick buck. The ubiquitous, under-rated Will Patton pops in briefly as a competitor for Michelle's affections.

Holly Hunter, who seems to get more diminutive with each passing role, continues to demonstrate the sort of post-Oscar role selection that Nic Cage can only dream of with a turn as a kindly AA meeting attendee. And, of course, what would a drug flick be without the presence of Dennis Hopper, who does a one-scene, elder statesman cameo a la William Burroughs in Drugstore Cowboy.

The most entertaining member of the rogues' gallery, though, that Fuckhead encounters, is the insane hospital orderly played by Jack Black. In his second scene-stealing performance of the year, after High Fidelity, Black earns big laughs as a pill popping, thoroughly disoriented co-worker of our hero's during one of his attempts to go straight. The highlight of this particular surreal episode comes as Black advances, armed, on a piece of hapless roadkill to the strains of "The Ballad of the Green Berets."

Befitting its title, as well as the repeated Christian imagery and references, Jesus' Son features redemption as a prominent theme. As FH comes to gain a greater understanding of himself and the world around him, the process is handled with a fortunate mixture of dark humor and genuine empathy.

As in The Crush, Maclean evinces a clever visual eye throughout, with original compositions that accentuate the absurdity of FH's trials and travails. Using the widescreen image allows her such liberties as a riveting split-screen injection session featuring Leary and Crudup.

Generally, the raft of supporting characters keeps Jesus' Son moving along at a decent clip, and the performances are uniformly fine. It's unfortunate, though, that a stronger through-line couldn't be devised, since the main relationship of the film seems somewhat forced and the whole ends up as something less than the sum of its parts.