Diana (Zosia Mamet), the neurotic twentysomething protagonist of The Boy Downstairs, wants to be a writer. But what sort of writer does she aspire to be? What books does she read in her spare time? Who are her influences? Unfortunately, the audience never finds out the answers to those questions throughout writer-director Sophie Brooks's film. Nor do we learn what drives her ex-boyfriend, Ben (Matthew Shear), to pursue a career in music. Unbelievably, we never even hear what his music sounds like.
That it's impossible to answer these questions reflects the fundamental narrowness of The Boy Downstairs. Endeavoring to give us a post-mumblecore spin on Annie Hall, Brooks seemingly fails to understand what made Woody Allen's film so appealing: its rich, multi-faceted characterizations. Brooks offers up two generic Brooklyn-dwelling hipsters whose halting, awkward style of banter will be more than familiar to anyone who's seen an Andrew Bujalski film or an episode of Girls. With their shaggy, low-key rapport, Diana and Ben seem like a perfectly nice couple, but, well, they're kind of boring.
That's a problem when the film hinges on the audience's investment in the outcome of Diana and Ben's relationship. The Boy Next Door picks up as Diana returns to New York from a stint abroad in London to focus on her writing. She soon moves into a picturesque brownstone owned by a widowed actress (Deirdre O'Connell), only to find that Ben lives in the same building. Brooks ping-pongs between flashbacks to the couple's brief but intense time together and Diana's fumbling attempts to at least be friends with her ex now that they're neighbors. Ben, the wounded romantic, rebuffs Diana, while she tries to convince herself that friendship is all that she wants from him, even though her deeper feelings for Ben are unmistakable.
Brooks has a feel for the ambivalence and lopsidedness of many relationships between twentysomethings, and she has an acute understanding of the way that people so often use major looming life events to avoid truly deciding what they want in life—as Diana does when a planned two-year stint in London serves as her pretext for breaking up with Ben. But, frankly, it's hard to care. Despite Shear and (especially) Mamet's nervous charisma, Diana and Ben are just too shapeless and dull for the nuances of their love life to hold much dramatic pull. This sort of story has been told many, many times before, often set against exactly the same backdrop of NYC bohemia. And so, without anything new or interesting to distinguish it—no narrative curveball, visual stamp, or distinctive writerly voice—The Boy Downstairs is simply superfluous.