Need proof marijuana kills brain cells? Catch "Next Day Air," a pot comedy trying to pass itself off as a Guy Ritchie/Quentin Tarantino multi-character crime caper. Weed is smoked liberally throughout the film, and I fear most of it was consumed behind the camera by director Benny Boom, who shows no discernable handle on the disorderly proceedings. "Air" is an interesting misfire, but often an irritatingly erratic viewing experience that would've profited greatly from a good old-fashioned dose of clear-headed concentration.

Leo (Donald Faison, "Scrubs") is a hapless delivery man, more interested in getting high than doing his job properly. Delivering a large box to clueless criminals Brody (Mike Epps) and Guch (Wood Harris), Leo doesn't realize the package was originally intended for the apartment across the hall, where nervous Jesus (Cisco Reyes) and girlfriend Chita (Yasmin Deliz) are waiting. Inside the box is a bundle of cocaine bricks, sparking dollar signs in the eyes of the petty thugs, with Brody calling his drug-dealing cousin Shavoo (Omari Hardwick) in to sell the stash. Frantic over the missing delivery, Jesus and Chita are visited by coldblooded drug lord Bodega (Emilio Rivera) to help retrieve the lost coke, chasing down Leo on the streets of Philadelphia and forcing him to right his original wrong.

While it might sound like a lightening-paced corker of a comedy, "Air" doesn't seem very interested in retrieving giggles. The screenplay by newcomer Blair Cobbs is more of a sobering, bloody cat's cradle of a caper, fixated on masterminding a tone of revolving danger and character idiosyncrasy over preserving a steady pulse to the storytelling. "Air" is all over the map, trying to horrify, tickle, and reassure in the same instant, and even after consuming the whole thing, I'm having difficulty understanding what Boom and Cobbs were aiming for with their motion picture. Every single subplot is malformed and increasingly tedious, with much of the primo comedic substance emerging from conventional drug jokes or silly criminal mishaps. The banter doesn't salvage much, as most of "Air" is handed over to actors with a limited hold on the art form of screen performance. Cobbs is scripting a whirlwind of violence and quirk, but it only manages to achieve a faint spark of enthusiasm.

I will give Boom credit for refusing to spray his rap video education everywhere. It's an amazingly tempered directorial job, more consumed with the gritty details of amateur criminal buffoonery than hyper editing and stylish dabs of violence. While his reserve is appealing, Boom's inexperience shows nakedly throughout "Air," particularly in the critical moments where the script wants to dance between slapstick and aggression. Instead of clever transitions between light and dark to keep the film's flow preserved, "Air" is often stunned by its own erratic behavior, a paralyzing spell Boom is powerless to break.

"Air" does showcase a certain bravery for an urban comedy, retaining lengthy character beats that are usually shooed away to make room for extra thug nonsense. I also enjoyed watching Faison's outstanding comfort with the camera, making me wish he didn't have what amounts to a glorified cameo in the film. "Next Day Air" has highlights, a few unexpected turns as well, but it all seems trapped in material that's too determined, guided by a director who's too inexperienced.