In "Laggies," Shelton has brought her light, heartfelt touch to her most familiar, movie-ready plot — a version of the back-to-school comedy rendered not with Rodney Dangerfield antics but the soul-searching of a direction-less 28-year-old Seattleite (Keira Knightley). Megan has spent her post-high school life procrastinating and earning a graduate degree in marriage and family therapy ("because I wanted to have honest conversations with people," she says) that she hasn't put to use, unable to relate to her clients. Annika, too, is a little lost, her mom having abandoned her and her father (Sam Rockwell), a divorce attorney who suspiciously observes the arrival of her daughter's clearly older new friend at their suburban split-level. The familiar notes — the wacky friend, the inevitable prom scene — to Shelton's film keep it from ever finding the kind of honesty its character crave. Just as the film doesn't want to be only an implausible romp, its characters — a slacker fleeing stereotypical marriage, a lonely single-father, a teenager who wants anything at all from her mom — want the confidence to break free of convention. "Laggies," an A24 release, is rated R by the Motion Picture Association of America for language, some sexual material and teen partying.