Ma Mary and Aunt Sarah are determined to put on a good show as they prepare for the highly anticipated class of 1977 school reunion. It seems like only yesterday that their own gang were beyond excited about the leavers' party. But will the truth come out about what really happened on that fateful night 20 years ago?

The gang bows out in this special extended episode which returns to Derry one year on, as the friends are preparing for their final year of school. It's the week of the referendum on the Good Friday Agreement but the timing could not be any worse as the highlight of the year, Erin and Orla's joint 18th birthday, threatens to be overshadowed. While the family try to get their heads around the possible outcome of the vote, the friends realise they may not be ready for what the future holds.