The director, Polly Findlay (an acclaimed British stage director making her first feature), presents all of this in a stately and fastidious prestige-teleplay-of-the-week way. Adapting a 2017 novel by Bernard MacLaverty (the script is by MacLaverty and Nick Payne), she creates a generous space for her actors, who turn what might have been a rather staid movie — and still at times is — into a meticulous duet.