Let's ignore Accidental Love when discussing David O. Russell's recent career; after all, he chose to be credited as "Stephen Greene" on that disaster following monetary and artistic disputes with the studio. Without counting that one, Russell has made three of the finest films of the 2010s with The Fighter, Silver Linings Playbook, and American Hustle. Along the way, he's honed his directorial craft to a science by relying on terrific ensemble casts to tell compelling stories about American life. Joy seems like it should have been a natural progression in Russell's development, since it appeared to have all of the hallmarks of his greatness on the surface. Unfortunately, the film is a step back for the director, but perhaps that's only because he's set the bar so high for himself. Joy Mangano (Jennifer Lawrence) is a struggling single mother living in her cramped childhood home on Long Island, and is employed in a dead-end job with an airline. Her ex-husband (Edgar Ramirez) shares the basement of the home with her divorced father Rudy (Robert De Niro), while her mother (Virginia Madsen) is a first-floor shut-in glued to her soap operas on television. Joy's true kindred spirit is her grandmother Mimi (an excellent Diane Ladd), who still believes that her thick-skinned but crafty granddaughter is destined for great things. While cleaning up some spilled red wine, Joy badly cuts herself on broken glass while ringing out the mop by hand. Something clicks in her industrious brain and she begins chaotically drawing up prototype diagrams for a new cleaning device, using her young daughters' crayons and construction paper as the canvas. Joy petitions Rudy's newest girlfriend Trudy (Isabella Rossellini), a wealthy widow, for a loan to kick-start production on her invention: a self-wringing and machine-washable mop. After much consternation from her endlessly meddling family, Joy convinces Trudy to fork up the loan and produces a first run of her design. She struggles to get the business off the ground and constantly flirts with bankruptcy, but things begin to turn around when she gets a chance meeting with Neil Walker (Bradley Cooper), the head honcho at the newly formed QVC home-shopping network. Soon enough, business novice Joy must fight to keep control of her fledgling empire as shady maneuverings threaten to send her back to obscurity. Jennifer Lawrence is as talented as any actor working right now. She's Russell's muse, and her first starring role for the director is clearly the film's main attraction. Lawrence deftly navigates the rocky terrain of both Joy's life and the unbalanced script she's been saddled with, and her beady-eyed intensity and wide emotional range allow her to command every scene. She more than holds her own alongside veterans like De Niro, Madsen, and Rossellini. However, Russell never settles on a tone for the movie, possibly because he doesn't trust his source material. To be sure, it's a daunting task to make a compelling flick about a mop and its creator, but Russell's uncharacteristically unsteady hand fails to locate a sense of triumph in this narrative. There's a recurring bit about a fake TV soap opera that's wholly unnecessary. That cathartic-looking scene from the trailer of Joy firing a shotgun adds nothing to the story. The ideas behind Joy are inherently subversive; you can probably count on one hand the number of Hollywood films that follow a woman's entrepreneurial journey. And the scenes at QVC provide the movie's best moments -- Lawrence once again has superb on-camera chemistry with Bradley Cooper. Yet the black-comedy bits about Joy's dysfunctional family just don't feel complete. Frankly, a lot of this movie could have used some tightening and cleaning up. All of this might sound a bit overly critical since, in the end, Joy isn't a bad film. It's just hard not to see that the pieces of a better, more complete picture got left on the cutting-room floor. Maybe it's time for Russell to step outside of his comfort zone and try something new; regardless, that shouldn't stop anyone from appreciating Lawrence's talent in Joy.