Caroline Crale, a beautiful woman, was convicted of poisoning her husband. But, like the nursery rhyme, there were five other potential suspects—each with their own motive. Philip Blake, the stockbroker, who went to market; Meredith Blake, the amateur herbalist, who stayed at home; Elsa Greer, the three-time divorcée, who had her roast beef; Cecilia Williams, the devoted governess, who had n…