Time is running out...

Jews in South West France are being hunted. As the Nazis close in, a desperate man leaves a coded message for his son.

Eighty years later, powerful men will do anything to prevent the deciphering of this code.

Former police detective Celestine Courbet is escaping with her partner, Jacques Lecoubarry, from tragedy and betrayal in Bordeaux. When they moor their barge in the small town of Lissac-sur-Tarn they have no inkling that they are about to be drawn into an increasingly complex and perilous investigation.

A young Parisian academic is brutally murdered in a quiet back street of the town. A second shocking murder follows.

To solve the murders, Celestine must decipher the clues from the ancient cloisters of a 12th Century abbey to the ruins of a deserted village in the woods. But as she gets closer, so does the killer and he has so much more to lose.

Set in a picturesque landscape of wide rivers and fruitful vineyards; as the mystery unfolds a terrible secret emerges, but does this provide proof enough?

Resolution requires one final desperate action on the hill of Calvary, but the risk is great...