A secret. A mystery. The destiny of three friends marked by a promise that they are about to break... Paris, 2006. Adriana, an aspiring writer in search of her path, receives an unexpected invitation. Her friend Gela is getting married and the place has not been chosen at random. The wedding will take place at Kylemore Abbey, in Ireland, the boarding school where the two friends shared a school stay marked by mysterious events. None of them can break the promise. What they did then: give up marriage in order to survive. But the three, united again, return to the inhospitable region of Connemara determined to clarify what happened that night in the summer of 1994, when they discovered the tragic story of the Henrys, the family that lived in the abbey long ago.