Marc works as a programmer at a big company in Barcelona. He realizes day by day that something strange happens around him as people become sick while they come out from buildings. It is only the beginning of a huge epidemic spreading across the planet though. Marc decides to escape from his shelter through the tunnels of the underground and find his wife Julie. He meets Enrique, another decided man who wants to approach his father at the hospital. Together they start a difficult journey to find their beloved ones and they will become best friends even if they don't really trust each other at its beginning. A very interesting idea gave this Spanish film a great opportunity to be a classic sci fi gem that is compromising. When cinematography is combined with an actual script, we can have an extraordinary result.