Charades with a Lunatic

"Roses are red, violets are blue. It's not quite dead, just like you." What was the meaning of Desmond's childish rhyme, phoned to his sisters just days before his death? What unnamed 'treasure' of great value did Bella's crazy great-uncle Desmond bequeath to his family? In a posthumous letter to be hand-delivered to Bella's great-aunts, Gilead missionaries just returned from Peru to Cornwall, England, Desmond Wildeve spoke of a priceless object hidden in the vast, cluttered family mansion ...