Everything in this life must have a zenith, a moment of maximum brilliance, and it’s a sound bet that sibling filmmakers Joel and Ethan Coen ("Fargo") have edged past theirs.

No longer hailed as maverick visionaries, the duo has settled into a sort of auteur dotage — that of being extraordinarily clever but rarely profound. A highbrow facsimile of the Farrelly brothers. That said, where else can one turn
for side-splitting riffs on Edgar Allan Poe and irritable bowel syndrome?

Though it lacks a sense of purpose and is strictly a low-stakes, low-payout sort of wager, "The Ladykillers" — based on the 1955 Peter Sellers-Alec Guinness comedy of the same name — is unquestionably amusing, a farcical caper yarn spun from the Coens’ limber, learned imaginations.

Set near a small-town delta on the Mississippi shoreline, the story is populated by the filmmakers’ usual collection of mutated caricatures and misfits. Foremost among them is Goldthwait Higginson Dorr, Ph.D. (Tom Hanks), a pompous, self-inflated classics professor with a speaking manner as cloying and Southern as Tupelo honey. Draped in a white silk suit and harboring a fussy goatee, Hanks ("Catch Me If You Can") gives his savviest comedic performance in years as Dorr, who guffaws at his own witticisms but is too obtuse to see that his favorite poem, Poe’s "The Raven," portends his own doom.

"Unmerciful disaster" awaits when Dorr rents a room from Mrs. Munson (Irma P. Hall), a bow-legged, churchgoing widow who rambles on about "fiery pits" and "beasts of Balthazar" and other biblical peril. Ostensibly, Dorr wants the room so he can rehearse with his church music ensemble in Mrs. Munson’s root cellar. The truth is a little more sinister: Dorr and his fellow "musicians" — including a former Vietcong tunneling expert named The General (Tzi Ma) — will use the cellar as a launching point to burrow to a nearby riverboat casino gaming office, which they will then relieve of the day’s revenues.

Naturally, Dorr and his conspirators are more Three Stooges than Ocean’s 11, and the heist falls victim to all manners of ineptitude, including dismemberment, bitter infighting — between oafish demolition man Garth (J.K. Simmons from HBO’s "Oz") and gun-toting homie Gawain (Marlon Wayans) — and good, old-fashioned greed. Somewhere along the line, pious Mrs. Munson uncovers the plot and threatens to go to the sheriff, forcing Dorr and his associates to contemplate her homicide, hence the title.

One problem: By the time murder enters the picture, we’ve long stopped caring how these machinations play out. The characters are too hollow and venal; they seem destined for the garbage heap the moment we see them, which is literally where they end up going, to the tune of Thomas Dorsey’s soul standard "Come, Let’s Go Back to God." "The Ladykillers" isn’t as lifelessly cynical as "Intolerable Cruelty," the Coens’ most recent and least-engaging effort, but it’s almost as numbing.

In lieu of tension and anticipation, the Coens whip up another savory salmagundi of mixed idioms: Black spirituals and intellectual snobbery, slapstick and poetic dread. Even in their least lacerating moments, these boys slay us.