Young Frenchwoman Mathilde searches for the truth about her missing fiancé, lost during World War I, and learns many unexpected things along the way. The love of her life is gone. But she refuses to believe he's gone forever — and she needs to know for sure.

A murder in Paris’ Louvre Museum and cryptic clues in some of Leonardo da Vinci’s most famous paintings lead to the discovery of a religious mystery. For 2,000 years a secret society closely guards information that — should it come to light — could rock the very foundations of Christianity.