The sharp, witty and enigmatic DI Annika Strandhed, as she heads up a new specialist Marine Homicide Unit (MHU) that is tasked with investigating the unexplained, brutal, and seemingly unfathomable murders.

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.