Paradise, the wised-up yet deeply heartfelt directorial debut of screenwriter Diablo Cody, shares the shape and flaws of its heroine the way a shell does its turtle-- it's like she secreted it. Like Lamb Mannerheim (Julianne Hough), a moneyed, home-schooled beauty chucking her God for one night in Las Vegas, the film is sprightly then mopey, alive then miserable, striding purposefully forward yet not going anywhere. Lamb's plan, arrived at after a plane crash leaves her arms, legs, and torso forever scarred, is simple yet vague: She'll corrupt herself in Sin City, and then—well, her mission's third act is as hazy as the story's. Lamb makes a couple of new best friends who take to her immediately for reasons the movie never makes clear—their common ground seems only to be that the same writer thought them up. Since the crew comprises Octavia Spencer, who aces Cody's allusional dialogue, and Russell Brand, who is never better than in supporting roles, they're welcome, even as their night grinds on without much happening. There's pleasure in the misadventures, especially that rococo Cody chatter, here less stylized than in her hit Juno and less consistently acute than in Young Adult. Here's Lamb's reaction when she gets a whiff of the toiletries in her suite's shower: "In my house we make our own soap. This stuff smells like a whore. I like it." Behind the camera, Cody smartly times these jokes, but she doesn't have the bigger-picture storytelling mastered. Lamb is angry, but still really nice, and sometimes too eager to say godawful things. The movie shares these traits rather than examines them.