Swiv, a nine-year-old living in Toronto with her pregnant mother, an actor who is raising Swiv while taking care of her own elderly, frail, yet extraordinarily lively mother, Elvira. When Swiv is temporarily kicked out of school, her Grandma becomes her teacher, and gives her an assignment: to write a letter to Swiv's absent father about life in the household during the last trimester of the pregnancy. In turn, Swiv gives an assignment to Grandma: to write a letter to "Gord," her unborn grandchild (and Swiv's soon-to-be brother or sister). "You are a small thing," Grandma writes to Gord, "but you must learn to fight." Through the astonishing, headlong rush of Swiv's voice as she records her thoughts and observations, Fight Night unspools the pain, love, laughter, and above all, will to fight across three generations of women in a close-knit family.