“Orphan Black” star Tatiana Maslany and “Downton Abbey” thesp Tom Cullen will premiere their new film, “The Other Half,” at South By Southwest on March 11, and Variety has an exclusive sneak peek at the drama, in which a grief-stricken man and a bipolar woman fall in love and try to forge a simple life together.

Speaking to Variety after her Emmy nomination last year, Maslany explained how much of a “passion project” the film is for herself and Cullen — who are also a couple off-screen and serve as executive producers on the feature.

“It’s about two people who are very broken and very much in love with each other and trying to make it work. It’s a very simple story but told really beautifully,” she said. “The director is Joey Klein, and I’m working opposite Tom Cullen and it’s like a family affair. It’s a real passion project for all of us — we’ve been attached to it for years, so it’s finally seeing the light of day, which is the most gratifying thing.”

In the film, Nickie (Cullen) is a self-destructive loner ever mourning the disappearance of his younger brother. Having abandoned a life of promise in his native UK, he has subsisted by drowning grief in alcohol and violence. On the fifth anniversary of his brother’s disappearance – and on the verge of reaching his nadir – he meets Emily (Tatiana Maslany). The two form an immediate, inseparable bond: it is a love at first sight deepened by a shared sense of sorrow. The film also stars Suzanne Clément, Henry Czerny, Deragh Campbell and Mark Rendall.

The Other Half” will make its world premiere in the Narrative Feature Competition at SXSW. It was written, directed and produced by Klein. Other producers on the project include Nicole Hilliard-Forde and Jonathan Bronfman, along with executive producers Cullen, Maslany, Jay Firestone, Vanessa Piazza, David Miller, Mark Gingras, John Laing, Julia Sereny and Jennifer Kawaja. Bobby Shore serves as cinematographer and James Vandewater edits, with Klein and Cullen providing the music for the film.