After Aggie Dunkirk's career is unceremoniously ended, she travels to Wisconsin, where her grandmother, Mumsie, lives alone in her rambling old home. She didn't plan for how eccentric Mumsie has become, obsessing over an old, unsolved crime. Mystery seems to follow Aggie when she stumbles upon the unsolved murder of a young woman - the details of which match Mumsie's case. In 1946, Imogene Flannigan comes home to discover her younger sister's body in the attic. Unfamiliar with the new world of criminal forensics, Imogene is nonetheless determined to stay involved. As her sister's case grows cold, Imogene vows to find justice . . . even if it costs her everything.