A man lacks self-confidence and is increasingly afraid of seeing the woman he loves move away when he looks to the future. One day, while running in the mangroves, he finds a mysterious bag. A woman looks to the past to understand the wrong turn their relationship may have taken. Two couples are confronted between fantasies, memories and reality with their fascination for a mechanical object that works by combustion. This object is the origin of a fire that stimulates them as much as it could destroy them.