Spain 1969. After the death of her brother, a young, dyslexic organist begins a forbidden love affair with an idealistic woman who pushes her to write a song and rebel against the highly censorious and conservative society ruled by the dictator Franco.

Hako and Marqués are two hitmen who have broken into the apartment of a former gang member in the neighborhood to collect a debt. However, nothing is as it seems, and they will soon discover that there is much more behind the legend of the Stray Dog.