THE SUMMER YOU WON'T FORGET. As Mel's husband moves out of the family apartment, a man, eerily similar to a past lover of hers, moves in upstairs. When the man's girlfriend joins him, Mel's obsession with the couple builds and the boundaries between the two homes begin to blur. The Couple Upstairs is a dazzling novel about a curdling infatuation, our compulsion to repeat mistakes, and the limits of reason in the face of desire.