At the very least, what The Da Vinci Code says about Jesus and the Church makes for fun speculation, and when Ian McKellen comes on and shows the supposed hidden messages in "The Last Supper" the movie comes close to being the cracking good yarn it should've been.
Tom Hanks, Audrey Tautou and Jean Reno do a good job of not overplaying their roles, and Sir Ian McKellen overplays his in just the right way, making Sir Leigh into a fanatic whose study just happens to contain all the materials for an audio-visual presentation that briefs his visitors on the secrets of Da Vinci's " The Last Supper " and other matters.
Nuns get whacked, the Crusades are uncloaked as the medieval equivalent of the current Middle East sham, and Da Vinci's The Last Supper hints at the human roots of Jesus, yet Howard and scriptwriter Akiva Goldsman, his usual partner-in-idiocy, are so afraid of offending ticket-buyers that any potential provocation ends in a lukewarm puddle.