Addie and her sister are about to embark on an epic road trip to a friend's wedding in rural Scotland. The playlist is all planned and the snacks are packed. But, not long after setting off, a car slams into the back of theirs. The driver is none other than Addie's ex, Dylan, who she's avoided since their traumatic break-up two years earlier. Dylan and his best mate are heading to the wedding too, and they've totalled their car, so Addie has no choice but to offer them a ride. The car is soon jam-packed full of luggage and secrets, and with four-hundred miles ahead of them, Dylan and Addie can't avoid confronting the very messy history of their relationship... Will they make it to the wedding on time? And, more importantly, is this really the end of the road for Addie and Dylan?