Stephen Frears’ Philomena hardly marks the first time Steve Coogan has played an ordinary fellow, but it feels like a definitive forward step in a peculiar and interesting career. To some, he’ll never stop being the British TV character Alan Partridge; to me, he’s always the guy from the under-seen Tristram Shandy, who pops up in brilliant cameos in all sorts of places (including Hot Fuzz). 

In Philomena, Coogan plays Martin Sixsmith, a former journalist turned political advisor who’s recently lost his job under vague and probably nasty circumstances. He’s politely surly, fairly dour and generally bored until an encounter at a party drops a human interest story — not at all his sort of thing — into his lap: A young woman has just learned that her mother has, for 50 years, been hiding a secret. As a pregnant young girl, Philomena Lee (played in her teens by Sophie Kennedy Clark and as an adult by Judi Dench) was sent to a convent, where she gave birth to a child that was taken from her. Philomena wants to find her son, and the nuns are far from helpful. Martin, slightly desperate for work, takes on the search and the story. (Game of Thrones’ Michelle Fairley has a tart, small role as his no-nonsense editor.)

The odd-couple push and pull of Martin and Philomena’s relationship propels Philomena as much as the search for the long-lost Anthony does. Casually snobby, cosmopolitan, impatient Martin grows angry at what he sees as unjust behavior from the nuns; Philomena, despite being kept at the convent for years to pay off her debt to the nuns, still goes to mass and believes in her god. She aches and is cheery in equal parts, and is baffling to Martin. The screenplay, co-written by Coogan and Jeff Pope and based on Sixsmith’s book The Lost Child of Philomena Lee, is uncommonly sensitive to what drives its characters, and to their different beliefs. The story is the sort of thing you couldn’t make up; no one would believe its moment of coincidence and kindness, pain and generosity. 

Woven into the relationship between Martin and Philomena, and between Philomena and the son who was taken from her, is the mythology of parents and children, the idea that any of us can really know who our parents were or who our children will be. The film is unabashed about tugging at the audience’s heartstrings, but it’s so artfully made (Frears does have some experience with heartstring tugging) that even a tinkle of weepy music or overlong flashback eventually fits into the whole. Go for Judi Dench, whose performance is as masterful as anything she’s done; leave with new regard for Coogan, who portrays Martin with a mix of uncertain purpose, building anger and reluctant understanding. Bittersweet and smart, Philomena is a character piece that carefully weaves in ugly parts of American and Irish history, a story that’s as much about hatred and misused power as it is about faith and forgiveness. 

PHILOMENA: Directed by Stephen Frears. Screenplay by Steve Coogan and Jeff Pope, based on the book The Lost Child of Philomena Lee by Martin Sixsmith. Cinematography, Robbie Ryan. Editing, Valerio Bonelli. Music, Alexandre Desplat. Starring Judi Dench, Steve Coogan, Sophie Kennedy Clark, Michelle Fairley, Anna Maxwell Martin and Mare Winningham. The Weinstein Company, 2013. PG-13. 98 minutes. Three and a half stars.