The Body is washed up on a Cornish beach, encased in a diamond-hard, glass-smooth cocoon, perfectly preserved, with open, staring eyes.The scientist must solve the mystery of Stone Man, and the other victims of what he suspects is a mutated Pinna nobilis, or king mussel.The mythology of the ancient land of Lyonnesse collides with Norse legend.Time is running out, for the victims and perhaps even the human race.