A fourth book, The World Turned Upside Down, was promised at the end of Nature's God but was never written; Wilson also had stated he intended the Chronicles to be a pentalogy.
Trilogy, as he blunders through Europe and America during the Enlightenment, constantly fighting to escape becoming a part of history.
The first time he is imprisoned in the Bastille, from which he escapes using Masonic techniques of concentration to help distract himself from the pain involved in climbing down from his tower.
The second time Sigismundo is imprisoned by a more mysterious group of captors, who seek to convince him that he is a descendant of Jesus Christ.
In 1989, Kenneth Lamar Noid, a mentally ill man, held two employees at a Domino's Pizza restaurant in Chamblee, Georgia hostage, and requested a copy of the series' second novel, The Widow's Son.