In may 1980, fiften-year-old Oscar Drai vanishes from his boarding school in Barcelona. For seven days and nights, no one knows his wherebouts...
His story begins when he meets the mysterious Marina. She takes hhim to a graeyard where they witness a macabre ritual. On the last Sunday of every month, a coach appears. A woman shrouded in black descend, holding a single red rose. She walks over to a gravestone that bears no name, only the emblem of a black butterfly...
When Oscar and Marina folowe her, they begin a journey that takes them to the heart of a forgotten, post-war Barcelona. Beneath the streets, a dark secret lies waiting...