When six ex-friends are invited to a winter wedding in Canada, the last thing they want is a reunion. But bride-to-be Bryn is desperate, so much so that she's offering to pay for their travel. But there's a surprise in store: Bryn hasn't booked them flights; instead, she's bought non-refundable tickets for the cross-Canada Christmas train.

Four days. Four days trapped together in a cozy train cabin, travelling through snow-topped mountains, frozen lakes, and glistening Christmas trees, over the most magical time of the year. It's a trip like no other, and Bryn hopes it will end their feud just in time for the wedding. One last chance at love…

But tensions on board are fraught. Cali and Luke are each other's One Who Got Away, Joss and Joe are the ultimate sibling rivals, and Sara is stuck with the people who always left her out. Not to mention Ember, Bryn's ex, who wasn't even invited and is on her way to crash the wedding.

Then a snowstorm hits and stops them—literally—in their tracks. Will they make it to the wedding? And will it be together?