This Is Christmas follows Adam (Alfred Enoch)
and Emma (Kaya Scodelario) as they make their daily commute from the
picture-perfect village of Langton to London for work. Every day they share
their journey with the same characters, but they all keep themselves to
themselves. But then one day, in the build-up to Christmas, Adam breaks the
unwritten rule of travel and starts talking to the strangers on the train,
inviting the whole carriage to hold their own Christmas party.