Duplass coming around to playing Kenneth the Time Traveler happened organically, says Trevorrow. "He was the missing piece of the whole project.  I didn't want him to be be a broad silly character, but a grounded real person who our heroine is falling in love with. We buy Mark as a real man. He has a naturalistic presence on screen. We asked if he would do it, and he said 'yes.'"

Duplass wasn't doing it for the pay check. "This is a tiny little movie," says Treverrow. "Mark was very eager to take on the challenge of a real character, not just playing another version of himself."

In fact several actors on the film had something to prove. "Parks and Recreation" star Plaza "wanted to show that she could go beyond the eye-rolling intern in the corner," says Trevorrow. "Mark wanted to show he could act, not just emote, as himself. Jake Johnson wanted to make clear that he was the great American actor, not just the funny guy on 'New Girl.'"

In fact, when they cast Johnson "New Girl" hadn't aired yet. "It was me knowing him," says Trevorrow, "wanting to show the world. Coincidentally other people figured that out at the same time. Now we have a big TV star in the movie."

One of Trevorrow's contributions was driving the movie in a more romantic, heartfelt direction. The first draft Connolly wrote was more of a "comedy mystery road trip movie, the same characters and scenes."

What could go wrong with this movie was the tone--it was a balancing act between comedy and drama. "All we did in every scene was to find the truth in the moment and make it honest," says Trevorrow. "You end up going deeper, not improvising comedy, improvising drama, but emotionally truthful moments. This was tightly scripted, but we took advantage of having Mark there and have everyone be willing to take time to open the scenes and have intimate moments. The difficult line to walk tonally: we felt it in the editing room, and followed our instincts all the way to keep people engaged and be romantic and funny."

One bit where Johnson flips up the nerdy intern's collar and pops on his sunglasses was improvised. "That was a result of getting in the room, we had the A and the B, what's the C and D? How can we make it richer?," says Trevorrow. In one case, Duplass threw a curve ball to Plaza, asking her a question she wasn't expecting, forcing her to give her honest answer. "It's not feeling manipulative to the actor, it's to add to everyone's game, always looking for how to find the best level."

As for the danger of leaning too sincere and romantic, Trevorrow says that he's "an earnest person by nature, my brain doesn't process sarcasm or irony. I'm gullible. I think people mean what they say. There's no shame in being romantic at all. I think people want to feel that sense of romance, which is rarely even attempted anymore."

But the R-rated movie also has sharp edges to it; Duplass is playing a guy who may well be crazy. And Johnson is a nasty character who says mean things about women.

The biggest anxiety came after Sundance accepted the film and Trevorrow agonized over changing the ending, moving away from the script. "I knew something was wrong, that people weren't feeling the way I had hoped.  So I did the opposite of what we had, and turned the movie upside down."

FimDistrict has been receptive to the filmmakers, allowing them not to put stars in the poster and to deploy biomarketing and social networking, "relying on people to tell each other that this is a movie that makes people feel good," he says.

As a writer who has been working within the studio system for a while, Trevorrow hopes that all his buds at the studios will now feel that they have permission to sell him to their bosses. "I like to believe that intimate moments between characters don't need to be relegated to independent films," he says, "can coexist with big exciting things happening, they are not mutually exclusive. Big movies coould use a little Mumblecore and humanity."

From his lips to Hollywood's ears.