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-Because of how Aringarosa, Bishop of Opus Dei, saved Silas after his escape from prison, Silas is overly loyal to him and the ways of Opus Dei
-Many gears have been set in motion as the plot is builds up, with Langdon and Sophie's investigation of Sauniere's death becoming more interesting, with Silas set out to do an unknown task backed by unknown higher-ups (the Teacher), and with the French police catching on to what is happening
-Dan Brown really knows how to write a page-turner; almost every chapter ends with something the character discovers that the reader doesn't know about yet, lulling the reader to keep on reading
-PHI-1.618-is the number of the Divine Proportion
-Updated antagonists: Fache, Silas, Aringarosa and company
-Supporting characters: Sister Sandrine of the Church of Saint Suplice