Francis gradually traces the neighborhood cats who descended from the strays involved in the experiments and is confronted by Pascal, who reveals himself to be Claudandus. Following Claudandus's murder of Preterius, he was taken in by Preterius's former assistant Ziebold and educated himself on Mendel's laws of heredity. In his pursuits, he saw an opportunity to create a breed of cat that would correspond to the primal ancestor of all domestic cats and be capable of wiping out humanity. The murdered cats, now including Joker, were deemed unworthy of breeding with the pure females that Claudandus had engineered. An additional obstacle in Claudandus's plot is the fact that he is terminally ill with stomach cancer. Although Claudandus deems Francis an ideal successor, Francis defies Claudandus's ambition and attempts to delete the data that Claudandus had gathered. The ensuing fight between the two results in a house fire, and the struggle ends when Francis disembowels Claudandus and leaves him in the burning premises, from which Francis saves himself and an injured Bluebeard.