"WANTED: Somebody to go back in time with me. This is not a joke. P.O. Box 322, Oakview, CA 93022. You'll get paid after we get back. Must bring your own weapons. Safety not guaranteed. I have only done this once before."

A few years ago, someone found that ad -- originally printed in the pages of Backwoods Home Magazine -- and republished it on the Internet. It caught on as a web meme, which means a bunch of people who enjoy insulting others used it as a target for snarky putdowns. People read the ad and chuckled at the rube who thought he could time travel (in fact, the ad was a goof placed by a Backwoods Home editor desperate to fill column inches). The most remarkable thing about 'Safety Not Guaranteed,' the new fiction film that takes that Backwoods Home ad at face value and wonders what would happen if it had been real, is the way it uses a target of modern day cynicism to tell a story about the importance of rejecting modern day cynicism.

The filmmakers, two former NYU film school buddies named Colin Trevorrow and Derek Connolly, don't use their want-ad-placing time traveler as an excuse for mockery. Instead, they see him as a figure of hope. Okay, so the ad was a phony. But imagine if it were true. Wouldn't that be cool?

The ad seems especially intoxicating to 'Safety Not Guaranteed's' protagonists, who all have their own reasons for wanting to travel to the past to right a wrong. Darius' (Aubrey Plaza) mother was killed when she was just 14. Jeff (Jake Johnson) has carried a torch for his high school sweetheart for more than a decade. Arnau (Karan Soni) has wasted almost his entire college career as a lonely virgin lost in a fog of video gaming. They all work together at Seattle Magazine -- Jeff as a reporter, Darius and Arnau as interns -- where they're assigned a story on the ad and its anonymous author.

The trio head to Ocean View, Washington, where they find the all-important P.O. Box and, eventually, its owner Kenneth (Mark Duplass). By day, Kenneth's a grocery store stock boy. By night, he consults on the Internet with nuclear physicists and steals lasers from nearby laboratories. He rebuffs Jeff's attempt to become his time travel partner, but he's more receptive to Darius, who takes his passion a little more seriously, or at least looks a lot more attractive when she pretends to. Ocean View also happens to be the home of Jeff's former high school fling (Jenica Bergere), so while Darius goes undercover with Kenneth in order to figure out if he's a certified genius or an authentic wacko, Jake reconnects with his old flame. The two stories run parallel, as each distrustful journalist finds their hard exteriors melted by the possibilities of love, not just in the past, but in the future.

Without spoiling Kenneth's secrets or the film's surprisingly ambitious finale, Trevorrow and Connolly arrive at a place that essentially turns the tables on the people who use the Internet primarily as an excuse to crap on others. They throw their creative weight behind the dreamers and the believers -- maybe because to be first-time independent filmmakers like they are, you better be a dreamer or a believer if you're going to make things happen. Their cast is totally hip, but their message is completely old-fashioned.

Speaking of 'Safety's' cast, it's almost like the starting lineup of the Hip Sitcom All-Star Team, with 'Parks and Recreation,' 'The New Girl,' and 'The League' all represented. But even with those talented comedians, the film is least effective when it's going for laughs. For whatever reason -- maybe because 'Safety Not Guaranteed" ultimately wants to expose sarcasm and irony as shabby excuses for genuine human interaction -- the actors' hearts never really seem into the sarcastic and ironic comedy of the early scenes, most of it from Johnson's Jeff, who hides his sentimental core behind a wall of macho bluster. Like Jeff, 'Safety Not Guaranteed' tosses out a lot of unfunny, superficial humor, but deep down, it has a serious, sentimental soul.

I'm not sure Trevorrow (the director) and Connolly (the writer) even care all that much about the idea of time travel. Their movie is lot less curious about the hows of temporal displacement than the whys -- why someone would go back in time, and what it would mean to all of us if they could. Kenneth (a far goofier and more manic -- but no less likable -- side of Duplass than he previously showed in low-budget indie comedies like "Humpday" and "The Puffy Chair") thinks he's searching for a partner to travel through time with. But what he's really looking for is a partner to travel through life with. After all, what is a relationship if not two people moving through time together? Granted, in that case, time travels in only one direction. But the risks faced and the leap of faith required are exactly the same.

‘Safety Not Guaranteed′ hits select theaters on June 8th and expands nationwide on June 22nd.

Matt Singer is a Webby award winning writer and podcaster. He currently runs the Criticwire blog on Indiewire and co-hosts the Filmspotting: Streaming Video Unit podcast. His criticism has appeared in the pages of The Village Voice and Time Out New York and on ‘Ebert Presents at the Movies.’ He lives in Brooklyn with his wife, dog, and a prop sword from the movie ‘Gymkata.’