After Aidan's rash decision in Galway, Rory is left to pick up the pieces of their incomprehensible past. And Cora is determined to help him. Even after he reveals a staggering secret of his own. Confused and afraid, Cora convinces Rory there’s only one thing to do now: confront the man who can answer the thousands of questions that have plagued Cora since she first met Mrs. O’Leary last summer. The man who harbors more secrets than anyone else. Seamus O’Leary. Together, Cora and Rory return to the secluded island of Inis Mor, where Cora finds herself trying to understand the man who left Mrs. O'Leary all those years ago, as well as the woman who started it all—in the form of her diary. Through Lia O'Leary's own words, Cora discovers what those early years in Oyster Beach were like. And then Rory makes a decision that will affect them all. Surrounded by the wild Atlantic waves of the Irish coast, Cora will finally come to understand the stories and years that shaped the O'Leary family, the O'Brien boys, and most especially, the boy who's stolen her heart. In , the mystery of the -recommended is spectacularly unraveled.