A butterfly, a creature that symbolises rebirth and new beginnings, flaps its wings to alter the world of Romina and Germán, a world formed by two parallel realities. In one, they grow up as siblings, trying to express their love without sexual consummation; in the other, they are two young people who strike up a strange friendship rather than succumbing to their feelings about each other.

In this film, the acclaimed director Marco Berger returns after Plan B, Absent and Hawaii, setting out in a radically new direction in both formal and narrative terms. Thanks to a thoroughly disconcerting screenplay, with two storylines brilliantly woven together, this film becomes a fascinating, unusual, and sensual game of mirrors.