The Last Spark depicts a world devastated by a virus that physically and mentally mutates people into their greatest fears. Decades after the outbreak and trapped in a single room, Glen, an aged researcher plays mind games with his captor Peter, an interrogator for a sinister cult. Glen is forced to recount stories from his research: a police call operator dealing with the first day of the outbreak, an insane personal trainer keeping captives for his own entertainment, an attack at a nightclub and a home invasion that is very personal to Glen himself. As time goes by, Glen fights against his own fears, but soon begins to let his sanity slip, bringing into reality his greatest nightmares.