Set in Galashiels, Scotland, I Swear follows the true story of John Davidson, a young boy in 1980s Scotland affected by Tourette Syndrome-a time when there was little understanding or sympathy for this neurological disorder. John struggles to find his place in the world, facing rejection from both his family and society. His only way of coping is to isolate himself and rely on strong medication. That is, until one fateful day, as a young man, he meets a unique woman named Dottie, who supports him on a journey that will change his life forever.