“Heart of Fire” is the name of a unique ruby from the collection of Catherine II’s jewelry. Precious stones, like people, have their own destiny, and it is not always cloudless. Under tragic circumstances, having left the capital of the Russian Empire, the rubies set off to wander around the world. Their red color is the color of the blood shed by those who sought, one way or another, to take possession of a jewelry masterpiece. Agatha Christie, as always, skillfully paints the ominous stories that happen every time to people whose life path intersects with fatal stones.