Breathe

In the near future, an environmental tipping point is passed that takes out all plant life. Without the release of oxygen from photosynthesis, atmospheric levels plunge to 5%, too low for people to operate without masks. Pockets of survivors exist made possible by various oxygen generator equipment. One such group is the Hudson family in Brooklyn. Darius is an engineer with sufficient skills to build his own homemade unit. Unfortunately, he discovers that his calculations regarding its performance are in error. The machine can only support two people in the long run. Thus, when his father dies in an accident, he insists he take the body to reside next to his wife's. It is really a ploy to sacrifice himself for the benefit of his wife Maya and brilliant daughter Zora. Zora misses her dad terribly. She frequently uses her ham radio to broadcast her thoughts about the technical projects they used to work on together. The signal is picked up by a surviving group living in a Philadelphia subway station. They send a trio of their community to find Darius's home so they can improve their oxygen generating capacity. The trio of Tess, Lucas and Mike travel the 100 miles in three days hoping to glimpse the Darius technology. They go about approaching for help in entirely the wrong way - through force. Maya does not respond well to their threats of violence in they are not complicit. Eventually, they are able to penetrate through all the security devices that Darius built to protect his family. The technical workings of it are too complicated for them to understand.