Complex sentence: In early 2000, HarperCollins published "Rule by Secrecy", which traced the hidden history that connects modern secret societies to ancient and medieval times, also reached the "New York Times" Best Seller list.
Split into simpler sentences: In early 2000, HarperCollins published "Rule by Secrecy", which claimed to trace a hidden history connecting modern secret societies to ancient and medieval times. This book also reached the "New York Times" Best Seller list.