Breathe follows a mother named Maya and her daughter, who are forced to live underground after Earth is made uninhabitable due to a lack of oxygen. Only short trips to the surface are made possible by a state-of-art oxygen suit made by Maya’s husband Darius, whom she presumes to be dead. When a mysterious couple arrives claiming to know Darius and his fate, Maya tentatively agrees to let them into their bunker but are they all they appear to be?