Two strangers meet in a subway car. Both bring their past with them. Both look from their present. Both will determine their future in that fleeting, and ephemeral, vital journey that brings them together briefly.

Alex and Ona have long since broken off their relationship. When everything seems to be over, Alex decides to come back into Ona's life by showing up at the home they once shared. As there is no one in the house, Alex decides to enter with the keys he still has. As he walks through each room remembering his past life, he hears the sound of the door: it is Ona, who does not know, yet, that their relationship was not broken for a simple matter.

Spain, early 20th century. Hildegart is raised and educated by his mother Aurora as the subject of a social experiment, to be the first truly free woman in the world, the one who will lead humanity into a new era; and, in order to achieve this goal, is insanely loved… until the moment when she becomes a young and gifted woman and actually tries to fly freely, away from the oppressive nest of her creator and guardian.