Imagine allowing an unfamiliar person into your home to make a phone call, only for them to vanish while you wait in the kitchen. Or did they really disappear? Félix, an architect recently separated from his girlfriend, resides in a sprawling mansion in Barcelona. He soon discovers the numerous nooks and crannies within his home. But could these be sufficient to conceal another person, an intruder leeching off his living space? Or is Félix simply losing his grip on reality?