Faithful Place, by Tana French.
Back in 1985, Frank Mackey was nineteen, growing up poor in Dublin’s inner city, and living crammed into a small flat with his family on Faithful Place. But he had his sights set on a lot more. He and Rosie Daly were all ready to run away to London together, get married, get good jobs, break away from factory work and poverty and their old lives.
But on the winter night when they were supposed to leave, Rosie didn’t show. Frank took it for granted that she’d dumped him-probably because of his alcoholic father, nutcase mother, and generally dysfunctional family. He never went home again.
Neither did Rosie. Everyone thought she had gone to England on her own and was over there living a shiny new life. Then, twenty-two years later, Rosie’s suitcase shows up behind a fireplace in a derelict house on Faithful Place, and Frank is going home whether he likes it or not.