Denise Sutherland is a syndicated puzzle author. Her puzzles appear in a range of publications, including the Reader’s Digest Mind Stretchers series, and she is the author of Word Searches For Dummies. Mark E. Koltko-Rivera, PhD, is a 32° Freemason and expert on the major symbols and ceremonies of Freemasonry. Using this expertise, he analyzed prepublication clues to uncover and blog about key elements of The Lost Symbol. He co-hosts the weekly podcast Masonic Central.