In a world ravaged by a mysterious spore that causes people to spontaneously combust, society teeters on the brink of collapse. The story follows a nurse named Harper Grayson, who becomes infected with the spore and discovers she is pregnant. As she navigates a landscape filled with fear and chaos, Harper encounters a group of survivors led by a mysterious figure known as the Fireman, who has learned to control the flames within him. Together, they strive to find safety and hope amidst the fiery apocalypse, facing both external threats and the darkness within themselves.