Mysteries of interest for March: “You Must Remember This,” by Kat Rosenfield (William Morrow) You Must Remember This (William Morrow) Marion Caravasios is the matriarch of a wealthy Bar Harbor family, beloved by her granddaughter, Delphine, tolerated by her children. On Christmas Eve, Marion disappears from her mansion, the Whispers, only to be found frozen beneath the waters of an inlet just beyond the garden.