Outwardly, Philomena (played by Dame Judy Dench) seems quiet and reserved, but inside she has pockets of sadness and intensity and courage. And occasionally she can surprise you and even be a little bit cheeky.

That's exactly what this film is like as a whole - it's gently paced and never bombastic or over-the-top, yet it features some incredibly moving moments, thought-provoking ideas, and even some hilarity. 

Inspired by the true story of Philomena Lee, it's told from the point of view of Martin Sixsmith (Coogan, who also co-wrote and co-produced the film), a recently retrenched government spin doctor who seeks to rebuild his writing career and pull himself out of a depression.

His ticket out of his existential hole is the "human interest story" of Philomena, an Irish woman who had her son taken from her 50 years earlier by the strict nuns that ran the "troubled girls" home where she lived, and soon the cynical Sixsmith and the devoutly Catholic Philomena are on the road in search of the long-lost son, sparking a journey that examines faith, tolerance, forgiveness, redemption and many other themes in between.

There is so much that is impressive about this wonderful film from Frears (The Queen, High Fidelity). The pairing of Coogan and Dench is a stroke of genius - their odd couple pairing provides not only the comedic spark but creates the platform for the story's religious, philosophical and moral explorations. 

Coogan is disturbingly good at playing these kind of snide snobs and is very much at home in his role, while Dench, an occasionally wayward accent aside, is brilliant, bestowing Philomena with exactly the right mix of resilience and naivety, sadness and humour, and dressing it all up like your favourite grandma.

It's that delicate balance that make this such a good performance, and it's the performances that are the driving force behind Philomena.

With a story that unfolds so gently in a step-by-step manner, it's the passion in the characters - the sarcastic patronising and then righteous indignation of Sixsmith and the quiet fortitude of Philomena - that help this be such a compelling film.

Frears wisely lets the dramatic moments unfold quietly. There is no swelling score or camera tricks - just subtle moments full of heart where the score steps aside and lets the actors and the story do the heavy lifting.

And like the balance in Dench's performance, Frears gets the juggling of the light and dark right, given the heartbreaking subject matter.

It's a film with depth, tackling big issues while managing to be an immensely personal story at the same time.

How accurate this portrayal of that personal story is ... well, that's up for debate - the ending feels slightly contrived and there's a sense that in the opening announcement of "inspired by a true story", "inspired by" are the key words.  

But amid all this, Philomena is laugh out loud funny amid the tearjerking moments.

If nothing else, it's worth seeing for the perverse glee of hearing Dame Judy say the word "clitoris".