“Small Mercies” by Dennis Lehane. One night Mary Pat’s teenage daughter, Jules, doesn’t come home. That same evening, a young Black man is found dead, struck by a subway train under mysterious circumstances. The two events seem unconnected. But Mary Pat, propelled by a desperate search for her missing daughter, begins turning over stones best left untouched — asking questions that bother Marty Butler, chieftain of the Irish mob, and the men who work for him, men who don’t take kindly to any threat to their business.