Sixteen-year-old Libby Winters lives in Paradise, a seaside town north of Boston that rarely lives up to its name. After the death of her mother, she lives with her father, Bent, in the middle apartment of their triple-decker home - Bent's two sisters, Lucy and Desiree, live on the top floor. A former soldier turned policeman, Bent often works nights, leaving Libby under her aunts' care. Shuffling back and forth between apartments - and the wildly different natures of her family - has Libby wishing for nothing more than a home of her very own.
Quinn Ellis is at a crossroads. When her husband, John, who has served two tours in Iraq, goes missing back at home, suffering from PTSD that he refuses to address, Quinn finds herself living in the first-floor apartment of the Winters' house. Bent had served as her husband's former platoon leader, a man John refers to as his brother, and despite Bent's efforts to make her feel welcome, Quinn has yet to unpack a single box.
For Libby, the new tenant downstairs is an unwelcome guest, another body filling up her already-crowded house. But soon enough, an unlikely friendship begins to blossom, when Libby and Quinn stretch and redefine their definition of family and home.