An Island Drifts follows a teacher, Glen, who witnesses a young primary six student, Andrew, involved in a troubling and much discussed incident that happened in school. Without a full grasp on the truth, Glen deals with Andrew objectively but Andrew is unable to comprehend the situation and this leads to devastating consequences, causing Glen to lose his job and question if he is to blame. He ultimately has to meditate on his actions if they align with his principles, as he heads into the future where he either will or will not forgive himself.