The "About Time" actor stars alongside sisters Kate and Rooney Mara in the cast of the upcoming Werner Herzog film "Bucking Fastard".

The production, which completed filming last weekend, was shot in Dublin, Sligo, and Slovenia and is expected to be shown to buyers at the Cannes Film Festival this month. 

The film, which is written and directed by Werner Herzog, is being produced by Ariel Leon Isacovitch and Agnes Chu along with Andrea Bucko and Emanuele Moretti of Cobalt Sky Motion Picture Group, and Clara Wu Tsai. 

"Bucking Fastard" marks the first time the sisters have worked together, with the film being based on the true story of inseparable twin sisters Joan and Jean, who live on the fringes of society.

The film also stars actor Orlando Bloom, who plays their rowdy ex-lover Gareth Mulroney, while Gleeson will portray Timothy, their government-issued social worker who is trying to help them adapt to modern life after the two become tabloid sensations.

Speaking about the film, Herzog said: "'Bucking Fastard' is a film that, for me, completes a circle in an operatic triptych with my previous films, 'Fitzcarraldo' and 'Grizzly Man'.

"We cannot see the world as Jean and Joan Holbrooke see it, but we do see how the world reacts to them – through the courts and the press, through those that want to help and those who want to use them, through the eyes of beasts both tame and wild, and even through their own echoes in the core of the earth."

Two-time Oscar nominee Rooney has previously filmed in Ireland, having starred in "The Secret Scripture" directed by Jim Sheridan.

Speaking on her time shooting here, she remarked to the Times: "I felt completely at home in Ireland. Except that doing the Irish accent was hard. It’s a hard accent to master and one that – even I can hear – often ends up being done horribly. Doing it was terrifying. Especially being on set with real Irish people."

Rooney most recently featured in the Orion Pictures drama "Women Talking" from writer-director Sarah Polley, while Kate is best known for starring in the FX series "Class of ’09" and is up next in the sci-fi thriller "The Astronaut".

Eagle-eyed fans had previously spotted the sisters shooting on Dublin’s Capel Street.

* This article was originally published on Extra.ie.