Kate Mara and Treat Williams have signed onto the indie crime thriller “Blackbird.”

Initially announced as “Kin,” pic stars Eric Bana and Olivia Wilde as sibling fugitives who cross paths with a young boxer (Charlie Hunnam) just released from prison.

Williams and Mara will play a father-daughter duo whose storyline intertwines with the main plot. Sissy Spacek and Kris Kristofferson co-star as the boxer’s parents.

Austrian helmer Stefan Ruzowitzky (“The Counterfeiters”) directs from a script by Zach Dean.

Mark Cuban and Todd Wagner’s 2929 Entertainment is financing the $25 million project, which Ruzowitzky has previously described as a modern interpretation of the American north.

Gary Levinsohn and Shelly Clippard are producing through the former’s Mutual Film Co., which optioned the rights from Dean and set up the project at 2929 earlier this year. Madhouse Entertainment is co-producing and Adam Kolbrenner is exec producing.

StudioCanal is selling international rights to the pic, which starts production next month in Montreal.

Both Mara and Williams were last seen in “127 Hours” for Fox Searchlight. Williams also co-starred alongside James Franco in “Howl.” Mara recently wrapped roles in “Ironclad,” “Ten Year” and “Arthur Christmas,” and she next stars in the indies “Peep World” and “Happythankyoumoreplease.”

Mara is repped by UTA and The Schiff Company, which also reps Williams along with APA.