After the death of the paranoid emperor Tiberius, Caligula, his heir, seizes power and plunges the empire into a bloody spiral of madness and depravity.
Several people disappear from and at the sea. Their bodies are found gnawed to the skeleton, even the marrow is missing. The scientists have no idea which animal could do such things. Dr. Turner begins to suspect that the company which builds a tunnel beneath the bay might have poisoned the environment and caused an octopus to mutate to giant dimensions...
Through the childhood and adolescence of Signor Giacomo Casanova (from his memoirs), this is a description of how people lived in 18th-century Venice: their customs, habits, medicine, religion, and--most of all--the omnipresence of hypocrisy.
