The crossword solution for the term OPUS __: 'The Da Vinci Code' SECT is DEI, which stands for 'Divine Eternal Intelligence'. This is a term used in the novel The Da Vinci Code by Dan Brown to refer to a secret society that is devoted to protecting ancient secrets. The society is led by the character Sir Leigh Teabing and is based on the Priory of Sion, a real-life secret society that was founded in the 1950s.