By Daniel D'Addario

“All of You,” a sales title premiering in Toronto on September 7, features a test that many viewers might not dare to take.

In the story, set in the near future, science has devised a way to determine a person’s true soulmate — if they’re willing to take the test. An unexpected answer comes between Simon (Brett Goldstein) and Laura (Imogen Poots), and their encounters over the years after Laura discovers who her ideal partner really is (hint: not Simon, whom she loves despite herself) take on an increasingly painful intensity.

“We wanted to tell a relationship story,” says William Bridges, the film’s director and, with Goldstein, co-writer. “And we found that by changing one thing in our world, we could unlock people’s perceptions of what true love is, and that was a very rich area for a love story.”