Marco and Claudia are a long-standing couple in crisis. They decide to go and live in a new apartment, hoping to improve their relationship. But Marco is almost convinced that his woman has betrayed him, and does everything to prove his thesis. The house they are in is very special. And there is a blue door that, according to the owner, can not be opened for any reason. Claudia claims that there is something behind that door, or even someone. Marco instead is a rational man, who struggles to believe in the existence of supernatural entities. Unfortunately for them, behind that door hides something much bigger than what they could imagine.