HAPPY CHRISTMAS Nothing makes Anna Kendrick happier than saying you're holding an invisible kitten.

TWENTY-SIX-YEAR-OLD Jenny (Anna Kendrick) is reeling from a bad breakup when she decides to move to Chicago to live with her brother, Jeff (writer/director Joe Swanberg) and his wife Kelly (Melanie Lynskey). When Jenny gets so wasted on her first night in town that she has to be carried home from a party, Jeff's inclined to chalk it up to youthful indiscretion—but Kelly worries that Jenny's behavior might compromise the safety of their home, and of their (adorable) baby. This tension between responsibility and "fun" forms the film's major conflict, which unfolds in organic, unpredictable ways.

As an adult human who's seen Pitch Perfect twice and is totally in thrall to Anna Kendrick, it pains me to point out that she was the weak link in Swanberg's insightful little comedy Drinking Buddies, which came out last year, and she's the weak link here, too. Swanberg asks his actors to improvise most of their dialogue; maybe that's why Kendrick's performance is so inconsistent. Granted, she's playing an unhappy and mercurial young woman, but Kendrick never manages to connect the dots between her character's various moods. Lynskey is far more compelling as a novelist who hasn't been able to find time to write since becoming a mom. Lena Dunham's great, too, essentially playing herself as Jenny's friend Carson—she's the best friend you wish you had, enthusiastic and fun to be around and full of observations like "I feel like you're a lot prettier than you think you are."

As an influential figure in the mumblecore movement, Swanberg's taken plenty of flack for making movies that are self-indulgent. In Happy Christmas, though, he seems genuinely interested in women's lives, and he's created characters whose lives are genuinely interesting.