What a mess.

Figuratively speaking, “Smokin’ Aces” is an uneven, herky-jerky roller coaster of a flick, a black comedy that wants to be a clever caper movie when it grows up.

Literally, I felt like I needed a shower when the credits rolled, from all the blood and body parts that splattered every scene.

This picture is the highly-anticipated original story from Joe Carnahan, who wrote and directed the acclaimed 2002 police drama, “Narc.” But it’s immediately apparent, with its snarl of story lines and ensemble cast of characters meant to be memorable, that Carnahan thinks he’s made a Quentin Tarantino film.

Ray Liotta and Ryan Reynolds play FBI agents assigned to spy on a dying mobster, the last bastion of La Cosa Nostra left in the country. When word gets out that the ailing don has ordered a hit on federally protected witness Buddy “Aces” Israel, a Las Vegas magician, the pair find themselves in a race to get to Israel before he’s nabbed by bail bondsmen or dropped by any one of a colorful roster of assassins.

Jeremy Piven plays Buddy Israel with contemptible excess. His “protective custody” is the penthouse suite in a Lake Tahoe resort, which he fills with prostitutes, cocaine and an entourage of bodyguards. The drawn-out scene-setting disguised as an FBI briefing at the start of the movie portrays Israel as a small-time hood who networked his way into the good graces of the Vegas mob, but by the time the story catches up with him in the penthouse, audiences only see him as a broken-down man at the end of his rope. Piven needed to retain a little schmaltz, a trace of schmooze for viewers to buy into his desperate effort to hang on to his glory days.

If you didn’t know that the cast in this movie was listed in alphabetical order, you’d think Ben Affleck had the lead role. His performance as a bail bondsman is good but brief; of his two ex-cop compatriots, one (Peter Berg) is hardly heard from and the other (Martin Henderson) follows a plot line that’s supposed to be quirky but feels contrived.

Two of the assassins, Nestor Carbonell and Tommy Flanagan, work alone. With steely professionalism, they infiltrate the hotel staff and subtly work their way toward Israel’s suite as the race unwinds.

What passes for black comedy in “Smokin’ Aces” is provided by the Tremor Brothers (Chris Pine, Kevin Durand and Maury Sterling), a trio of neo-Nazi crackheads who live for mayhem. Armed with all manner of destructive implements and reminiscent of the sociopaths in “Road Warrior,” they’re the antithesis of subtle.

The only hit men with any depth of character are actually hit women Alicia Keys and Taraji Henson. Their plan is to send a dolled-up Keys in with the next round of prostitutes, backed up by firepower from the neighboring building courtesy of Henson. Though these two had more lines to memorize than their colleagues, their speeches are self-serving and don’t advance the story one bit.

The biggest disappointment in this star-studded troupe is Andy Garcia as the deputy FBI director in charge of the case. His primary function seems to be filling out the suit in the bureau scenes – normally a master of low-key intensity, he’s simply wooden here, and appears to be attempting a light Southern accent. (He must have hired Kevin Costner’s dialect coach, because it’s hideous.)

The movie belongs to Ryan Reynolds, hands down. He and Liotta are the only characters in the story viewers care about enough to believe in, and his performance here is a credit to his already-multifaceted career. Let’s hope he rises above the ashes of “Smokin’ Aces” to keep making better movies.