Jamie Dornan, Ben Mendelsohn, and sisters Jemima Kirke and Lola Kirke are starring in the independent dramedy “Untogether.”

Dornan, the star of “Fifty Shades of Grey,” will portray a successful writer who has an affair with Jemima Kirke’s character, a former teen prodigy and heroin addict trying to become a writer. Lola Kirke will play her younger sister who has an older boyfriend — played by Mendelsohn — and is drawn to an even older charismatic Rabbi.

Emma Forrest will direct from her own screenplay in her feature directorial debut. It’s also the first feature in which the Kirke sisters will appear together.

Producers are Scott LaStaiti, Luke Daniels, and Brandon K. Hogan. Executive producers are Jeff Rice, Jeff Elliott, and Chad Moore. Production begins on Oct. 17.

Elliott and Moore’s sales company, Green-Light International, will be selling “Untogether” at the Toronto International Film Festival.

Dornan is starring in the sequels “Fifty Shades Darker” and “Fifty Shades Freed.” He also toplined “Anthropoid” with Cillian Murphy and will appear in the Netflix film “The Siege of Jadotville,” due to be released in October.

Jemima Kirke stars on HBO’s “Girls,” and her film credits include “Tiny Furniture” and the upcoming “The Little Hours.” Lola Kirke’s credits include “Gone Girl,” the upcoming Tom Cruise movie “American Made,” and the series “Mozart in the Jungle.”

Mendelsohn stars in Netflix series “Bloodline” with Kyle Chandler and will be seen in “Rogue One: A Star Wars Story” and Steven Spielberg’s “Ready Player One.”

Dornan is repped by UTA, Troika in the U.K., and Sloane Offer Weber & Dern. Jemima Kirke is repped by CAA, MGMT Entertainment, and Schreck Rose Dapello & Adams. Lola Kirke is repped by ICM Partners and One Entertainment. Mendelsohn is repped by CAA, United Management, and Fred Toczek. Forrest is repped by CAA, and Casarotto Ramsay & Associates.