Imagine an ABC sitcom based on David Fincher’s Gone Girl, and you’ll get an idea of what this lightweight comic mystery is like. Anna Kendrick stars as a type-A single mom in suburban Connecticut who becomes friends with the bitchy, alcoholic mother of one of her son’s classmates (Blake Lively, clearly relishing the role). When the friend disappears, Kendrick sidesteps the police and begins searching for the woman herself. Screenwriter Jessica Sharzer, adapting a novel by Darcey Bell, toys with the idea that Kendrick’s fascination with Lively stems from a repressed desire to be bad, but she doesn’t develop this psychological insight to any meaningful end; likewise, Kendrick and director Paul Feig (Bridesmaids) quash the story’s darker implications by insisting on making the heroine likable at every turn. There are enough outlandish plot twists to hold one’s attention, and some of the one-liners are funny—if you aren’t looking for depth, you may be entertained.