The film starts in Afghanistan where an APC is on patrol while the passengers including Davy Henshaw and Ally are nervous as to their survival, before an ambush happens. Some time later Davy and Ally, recently discharged, return to their homes and families in Edinburgh after their Afghanistan tour. Ally returns to his girlfriend Liz, a nurse who is Davy's sister. On Davy and Ally's first night home Liz introduces Davy to her English friend and colleague Yvonne at a pub. Liz and Yvonne take part in some drunken story telling, a Scottish tradition. Following from their blind date Davy and Yvonne strike up a romantic relationship as Ally and Liz consider their future as a potential married couple. Davy's Dad Robert "Rab" Henshaw receives a letter from, and later meets, Eilidh, a daughter he didn't know he had; the product of an affair early in his marriage. As Ally explains to Davy that he intends to propose to Liz during the 25th wedding anniversary party for Davy's parents Rab and Jean, a bartender, who overheard the conversation offers Ally advice on how to propose. At the anniversary party Rab serenades Jean. During the party, Jean discovers the letter still in Rab's jacket and is outraged at Rab's infidelity. Ally then proposes to Liz, who turns him down. A mass brawl develops and Yvonne is horrified at Davy's aggression. Jean is horrified to hear from Rab that he intends to keep seeing his newly found daughter. Jean stops speaking to him and he is seen sleeping on the sofa. Eventually, Jean feels guilty and blames herself for the deconstruction of her family but her colleagues at the Scottish National Gallery reassure her that none of these events were her fault. Meanwhile, Rab is out buying the ingredients for a special meal he intends to cook in the hopes of reconciliation with Jean. As he returns home, he suffers a heart attack on the doorstep and is admitted to hospital. Rab recovers, and Rab and Jean reconcile. Jean agrees to let Rab see his daughter and has brought her to the hospital to see him. Yvonne and Davy have reconciled. However, Liz and Ally's relationship has dissolved. Ally re-enlists, while Liz accepts an offer of a job nursing in Florida. After an argument with Davy, Yvonne prepares to leave Edinburgh. However, before she can reach Waverley railway station, Davy catches her and declares his commitment to her in Princes Street Gardens where they reconcile for a second time. The scene cuts to Jean & Rab singing verses of the song to each other; Ally on patrol with the army, presumably sings to Liz who is shown at work in America opening a letter from Ally.
The film had grossed US$8,780,874 in its run as of 2014. On its first week it debuted at number three on the UK box office with £770,000. The following week it rose to number two with a weekly take of £732,296. The film received positive reviews. It holds a 90% approval rating on Rotten Tomatoes, based on 41 reviews, with an average rating of 7.1/10. On Metacritic, the film has a weighted average score of 66 out of 100, based on 7 critics, indicating "generally favorable reviews". Writing a four star review in The Observer, Mark Kermode said "I shed a tear within the first 10 minutes, and spent the rest of the movie beaming like a gibbering, love-struck fool". Tara Brand writing in The Irish Times likened it to The Umbrellas of Cherbourg and Cath Clarke writing in Time Out described it as "a wet, sloppy dog-kiss of a film".
