With one foot in mumblecore and the other in Saturday Night Live, this modest comedy with a soft sci-fi edge has been scoring strong reviews around the country. Many of those writers are openly enamored of Aubrey Plaza, who plays the sullen April Ludgate on Parks and Recreation, in a leading role written for her. I confess to not being a fan: She reminds me of a taller, snarkier Ellen Page, and while she is undeniably attractive, she has a tone of voice that makes everything she says sound like “Whatever.”

Here she plays Darius (an implausible name that I suspect is meant to remind us of the 1990s MTV cartoon Daria), a directionless college graduate working as an intern at Seattle magazine. Despite having no apparent interest in journalism (or for that matter anything else), she agrees to go on an assignment with staff writer Jeff (Jake M. Johnson) and fellow intern Arnau (Karan Soni), a shy Indian student. Their goal is to smoke out the guy who placed a classified ad in a nearby small town for someone to time travel with him. (The film’s title comes from the ad, following “Must bring your own weapons.”)

Locating their quarry, Jeff almost immediately antagonizes him, which doesn’t bother him much: His real goal is to hook up with his high school girlfriend, who lives here. (Yes, it’s his own kind of time traveling.) That leaves Darius to try to dig the story out of Kenneth (Mark Duplass), a grocery store stock clerk.

Duplass, who with his brother Jay made a series of low-budget films that are central to the mumblecore movement but of late has moved into acting in other indie films, is the best thing about Safety Not Guaranteed: He treads a line between likeably quirky and disturbingly weird that gives the movie its tension. Is he for real or is he nuts? And will the answer matter to (surely I’m giving away nothing here) Darius’s growing attraction to him? Director Colin Trevorrow and writer Derek Connolly (neither of whom are British) avoid a lot of pitfalls that might be expected in what is essentially a feel-good romantic comedy, which is of itself an accomplishment, even if little else here seems likely to linger in the memory.

Watch the trailer for Safety Not Guaranteed