A young man from a high-bourgeois family, Henrique receives mysterious phone calls from a woman at the barracks where he is serving in the military, which attracts him to meetings without consequences.

Amaranta Cano, daughter of Carlos Cano, reconstructs, in a journey connecting Andalusia with Portugal, the events that took place on the eve of Three Kings Day in 1985: a murder, a mysterious woman, and a setting marked by the border culture between Ayamonte and Vila-Real de Santo António, with smuggling as a backdrop. The documentary not only delves into the historical and social context of the song, but also pays tribute to Portuguese fado, a musical genre that deeply fascinated Carlos Cano, as well as its most emblematic author, Amália Rodrigues. Throughout the narrative, Amaranta talks to key witnesses of the event and prominent artists such as Teresa Salgueiro, Antonio Chainho, Rozalén, Raúl Rodríguez, and Martirio, who perform their own versions of the legendary song.