I’ve scoured the memory, but I can’t recall a more uneven onscreen duo than Val Kilmer and Robert Downey Jr. in Shane Black’s leisurely new buddy-thriller, Kiss Kiss Bang Bang. Kilmer’s in a perpetual awkward pose, earnestly proffering his lines like model sailboats; Downey’s a brilliant tour-de-force, deftly vacillating between intensity and nonchalance, turning jokes into jokes about jokes.

Auteurist dilettante that I am, I’d normally attribute Downey’s performance to commensurately subtle direction, but no dice. A screenwriter’s insubordination hits me rarely, but wordsmith Black is a special case, a longtime Hollywood staple (see: the Lethal Weapon series) whose primary virtue in the director’s chair is simply doing justice to the jazziness and self-reflexivity of his deliciously macabre screenplay. His visuals are pleasingly glittery, and on isolated occasion indelible, but mostly reflect a hardened efficiency. Yet despite a similar programmatic nature to Black’s storytelling, his pathos and wit hit the spot. For a first-time helming effort, Black’s sensibility is strikingly felt; calling such an enervated, world-weary work a debut feels wrong, and in terms of Black the writer, it is wrong.

Certainly, at least half the credit for Downey’s spectacularly rich work goes to how Black has imbued him with myriad contradictions. Downey is Harry Lockhart, an NYC-hoodlum-made-L.A.-socialite whose secondary milieu seems both a welcome divertissement and a preposterous, seething web of artifice. He's preternaturally acerbic, but also brims with the frazzled neuroses of an over-esteemed would-be; think Woody Allen doing Philip Marlowe.

Part of Harry’s charm is his integral part in the movie’s self-consciousness. He narrates us along with an air of equal parts contempt and self-correction, speeding along through the facts as though drooling for a paycheck but spurning himself later for eliding details. Said narration doubles as sub-Flaubertian free indirect discourse, now and again impeding on the action proper; non-fans of the impossibly neat resolution Spielberg opted for in War of the Worlds, in particular, will dig Harry’s winkingly abortive stab at the Immaculate Reconciliation.

But it’s not all gags and jitters; there’s a moving immediacy to Harry. One especially explosive scene – I’ll try to be vague – forces Harry into the role of an avenging angel, why and for whom he doesn’t understand. Downey’s execution, in both senses of the word, is suffused with the genuine urgency of cacophonous feelings boiling over rationale. Suffice to say, the derisive schoolyard taunt, “tough guy,” suddenly and unexpectedly burns like hot coals.

You may have noticed I’ve conspicuously evaded a plot summary, and that’s in part because conveying the story’s density and refraining to divulge its secrets is a tricky balance, and in part because it’s finally kinda irrelevant. Your neighborhood adenoidal pedant’s quibbles aside, the spirit of Kiss Kiss, one of cynical resignation and tremulously relit old flames, quashes the pull of its labyrinth modern-noir mechanisms.

Its world is vaguely Lynchian, minus of course the metaphorical transmutations: movie stars and ghosts, living harsh realities and harsher dreams, lose themselves in the tragic fog of indistinction. The thematic DNA is ultimately too intricate and self-involved to give much about, but what the film lacks in ideational heft or originality, it compensates for in brazed, ornery wit, not to forget Michelle Monaghan in a slinky santa suit. In the company of his withering, fastidiously humorless contemporaries, Black is an efficacious genre filmmaker with fingers crossed slyly behind his back, and his film is a firmly palpitating beacon of hope.