Part mystery, part family drama, The Last Thing He Told Me by Laura Dave is impossible to put down. When Hannah Hall's husband of just one year disappears, he leaves a note begging his wife to "protect her." Hannah quickly surmises the her in question is her husband's 16-year-old daughter, who may hold the key to unraveling his secret past. (This one is set to become a miniseries starring Julia Roberts soon, so you're going to want to read it ASAP.)