A spanking-new tin can, secretly placed among the rows of Mrs. Florence Gentrie's preserves, contains not a speck of food—but it does carry one very damning clue to a murder that took place right next door. Such an unsavory discovery in such an unlikely place can't help but pique the curiosity of a dedicated mystery hunter like Perry Mason.But the real mystery about this murder is who—and where—is the victim? Upstairs neighbor Elston A. Karr heard the telltale sounds of foul play, but his foul temperament (and his own dark secrets) make him most uncooperative. It takes a second murder to clear up the mystery of the missing body—and to make Perry Mason the next prime candidate to disappear.…