The Gleesons previously appeared together as Bill Weasley and Mad-Eye Moody in the Harry Potter blockbusters.
Calvary is about what happens when a man enters Father James' Catholic Church confessional and tells him he is going to kill him a week hence. The man confides he was molested as a child by a now-dead priest and says he wants to make headlines by slaying an innocent cleric in the pedophile's stead.
Father James spends the week reconnecting with his adult daughter, who is recovering from a suicide attempt, and talking to his parishioners, many of whom are lonely, angry and bitter, until the day arrives when he must meet his fate and possibly sacrifice his life. Brendan Gleeson plays the good priest, while Domhnall portrays an unrepentant murderer he visits in prison.
Asked by UPI in a recent phone interview what it was like to share a scene with his son under these circumstances, the elder Gleeson described it as "very odd."
"We basically didn't speak for about a week beforehand and got through it and gave as good as we got to each other on opposite sides of the table," he recalled.
"It was great when it was over, but it also was something I was kind of looking forward to and to have it in a film of this nature I was, obviously, very, very proud of him. But, also, just it was a real treat to engage with an actor of that quality. Outside of the relationship and all, I think he did an amazing job on it."
McDonagh also remembered capturing those gripping moments on a "tough day" of shooting.
"That was a very dark scene. It was very intense. We shot it in just one day. It was like a prize fight, I suppose, between two sort of evenly matched opponents in the level of darkness that was going on. I think that was the one day my brother turned up on set," the director told UPI in a separate interview, referring to playwright and filmmaker Martin McDonagh, who directed the elder Gleeson in the movie In Bruges. Domhnall also starred in the Broadway production of Martin's play The Lieutenant of Inishmore, and both Gleesons appeared in his short film Six Shooter.
"[Martin] hadn't read the script [for Calvary] and he turned to me after a few minutes in and he said, 'I thought this was supposed to be a comedy.' He didn't know what was happening at that point," John Michael McDonagh related.
"The initial intent with the film, it was meant to be much more of a black comedy type film, but when you get all of these really great actors involved, they find depth to the characters and it becomes a much deeper and much more dramatic movie and much more somber, I suppose. But that's good."
Co-starring Chris O'Dowd, Aidan Gillen, Kelly Reilly, David Wilmot, Pat Shortt and David McSavage, Calvary is earning rave reviews from critics. It opens is U.S. theaters Friday.