THIS year’s Edinburgh International Film Festival opened with this heartfelt hug of drama from director Marc Turtletaub, one whose pieces fit together snugly and sends you away with gentle sense of wonderment about finding your own happiness in the world.

Kelly Macdonald plays Agnes, an American wife and mother whose time spent running the family home while her husband, Louie (David Denman), is out at work has long been taken for granted. Cooking, cleaning, grocery shopping, even baking her own birthday cake; you get the sense right away that she’s both comfortable with her set routine and discontent with the mundanity it brings. Sound familiar?

Her life starts to change, however, when she receives a 1000-piece jigsaw puzzle as a birthday gift. After completing it in a quick time that suggests a natural talent, she heads to New York City to buy more from the same shop – geographically just a short train ride away but worlds away from her comfort zone. There she notices an advert asking for a puzzle partner and plucks up the courage to reply.

This leads to her meeting reclusive and eccentric jigsaw champion Robert (Irrfan Khan) who, as it turns out, wants to enter a national puzzle competition with her as part of a doubles team. It’s here where the film finds its make-or-break point; you either believe the relationship and how it enriches a bored life or it falls down as cloying and forced.

It worked for me and from that jumping off point it became even more endearing and quietly enlightening, with an uncommonly perceptive touch when it comes to behaviours of people unsure of themselves yet excited about what a new prospect can do for their confidence, self-worth and measure of happiness.

Macdonald is predictably wonderful in the lead role of a woman disenfranchised and increasingly confused by her docile suburban life, delivering a performance that crucially avoids two-dimensional showiness to bring an understated nuance that packs a punch in its own unobtrusive own way.

Khan also delights with a refreshingly different role than we’ve seen him in before, turning what could have been a merely clichéd tool for the main character’s self-fulfilment into someone genuinely moving in his own right.

Some of the film’s most effective scenes are simply those where Agnes and Robert are sitting across from one another, working together to complete a jigsaw that, time after time, represents them being able to complete something perfectly as their relationship blossoms.

It’s also very well observed in its exploration of her role as a mother of two vastly different sons, the laid back Gabe (Austin Abrams) and more awkward Ziggy (Bubba Weiler), caught between maternal instinct and wanting to be her own person, as well in its depiction of marriage.

Denman brings to the role of husband Louie a believable sense of complacency that morphs into self-righteous bewilderment and indignation when he starts noticing his wife’s sudden change in behaviour. Owing to the little details of looks, tones of voice and heated reactions, their marriage feels real and natural, to the point where it hurts when it starts to rupture.

Working from a graceful script by Oren Moverman (The Messenger, Love & Mercy), Turtletaub’s film is a well intentioned and well crafted slice of gentle drama full of warmth, charm and with more than enough worthwhile things to say about what it means to rearrange the pieces of your life to better suit your picture of happiness.