The Torments of Galileo

In the fourth volume of the series of books about "Detective Galileo," the battle between the criminal and the brilliant physicist takes on colossal proportions. As usual, science helps find a way out of the most mysterious situations. An anonymous letter arrives at the Tokyo police department from a person calling himself "The Hand of the Devil." In it, he states that he plans a series of murders and throws a personal challenge to associate professor of Taito University, Manabu Yukawa. Why did the criminal choose Yukawa as his target? How does he manage to kill people in such a terrifying way?