It started with a letter... It's hard for Carol to admit her failings. Unhappy in her marriage and with a teenage daughter who will barely converse with her, she feels trapped. So she puts pen to paper; well, it seems less daunting than airing her thoughts aloud. She isn't expecting anyone to read her letters, so she doesn't address them. Instead, she marks them with a smiley face and pops them in the post box.
Albert's retirement day at Royal Mail looms and he's given one final task; organise the 'lost letters' that have been piling up in a room behind the sorting machine. Amongst the letters addressed to Santa, he arrives at one with a smiley face drawn in place of an address. Albert opens the letter, unaware that in doing so his world would never be the same again.