The rest of the story takes place during the car trip to the airport, with the leaders given the opportunity for a brash, intimate and at times amusing discussion about living through The Troubles - as men rather than politicians. Once you're over fixating on Spall's oversized dentures, you can appreciate how beautifully Spall and Meaney work off each other.
It's a tough job explaining how Paisley and McGuinness overcame their prejudices to reach an understanding; eventually going on to be known as The Chuckle Brothers. The task is at times too big. The script works hard to sum up each side's perspective but often feels like a citation of the conflict's timeline. The proposed role played by M15 in the success of the agreement may be the hardest pill to swallow.
Beyond this however, as politics around the world becomes increasingly partisan and zero-sum it's a relief to be reminded that, on occasion, sense can prevail.
Cast: Timothy Spall, Colm Meaney
Director: Nick Hamm
Rating: M (Offensive Language)
Running time: 94 mins
Verdict: An interesting but polarising interpretation of history.