Escaping revolution and a ship's mutiny, 17th-century naturalist Edward Popple and his daughter Rosamund find refuge on an uncharted island in the Indian Ocean. Popple is a man of passions - for Rosamund and for scientific discovery. On the island they encounter Lou Lu, a Chinese eunuch, and his charge, Taizao, an impotent princeling, lost on the way to Rome to petition the Pope. They have a yellow rose. Like the crossing of Chinese and European roses the crossing of the two cultures through passionate love and procreation might also prove evolutionary - or will it?