It was a classically indie shoot, filmed at Passon's Montclair, New Jersey home with her two children playing Abby's and Kate's kids. Before the shoot, Weigert spent several days living with Passon and her family. "There was a lot to just sort of observe that was just right there," she told me. "You're stepping into a very ready-made world."

Even with her past directing experience, Troche said she learned from Passon's self-assured, even-handed approach:  "I stood on the sidelines going, 'oh my god, I want to do this.'"  Because they were shooting on digital, Passon would leave the camera running after she called cut and just "see what [the actors] would do," as Troche put it.  Some of these un-directed, quasi-improvised moments made it into the final cut.

Weigert had no qualms about taking on a role as sexy and exposed (both physically and emotionally) as Abby.  When I asked her about it, she referenced Helen Hunt's performance as a sex therapist in "The Sessions," and the subsequent endless questions during Q&As about Hunt's performances during the film's sex scenes.  "You have to be in a place where you're feeling comfortable in your own skin," she told me.  "There's something about a woman taking her clothes off, period, that people get churned up about."

"Concussion," which opened this year's LGBT-focused NewFest in New York City a few weeks ago, made a splash at Sundance this winter and was scooped up almost immediately by the Weinsteins' RADiUS--in what was reportedly a seven-figure deal.

For Troche, it was a serendipitous case of déjà vu: her debut feature, "Go Fish," which focused on a group of lesbian friends living in Chicago, enjoyed an almost identical trajectory at the fest almost 20 years ago.  Like "Concussion," it sold after just one screening.  "It felt a little full circle to me," Troche admits of the two films' synchronicites.

It's unlikely "Concussion" will be a big hit--it might well be too sexy and edgy for some audiences, although Troche plans to push for some well-deserved awards nods for Weigert's performance and Passon's capable directing.  But even if it ends up being a lower profile film, "Concussion" feels like it's at the leading edge of a new kind of gay cinema that focuses not on its characters 'gayness' but everything else in their lives that interacts with their sexuality.  The stories are familiar; its the characters who are new--characters who in the past have been so categorically underrepresented.

Sometimes, as Abby learns, it takes a blow to the head to look at the things we already know through new eyes.

"Concussion "opens in Los Angeles and New York on October 4.