The 20th addition to the marvelous, bestselling "Cat Who . . . " mystery series finds Lilian Jackson Braun in fine form. It's spring in Moose County and newspaper columnist Jim Qwilleran and his remarkable felines, Koko and Yum Yum, are caught up in intrigue once again, this time investigating the death of an elderly woman in a suspicious fire and the mysterious break-in at the newly opened art museum (Mystery/Detective)