West of France, 1989.

A weeping killer deposits the unconscious body of nineteen year old Lucie Martin, her head wrapped in a blue plastic bag, into the water of a picturesque lake.

Lot-et-Garonne, 2003.

Fourteen years later a summer heatwave parches the earth, killing trees and bushes and drying out streams. In the scorched mud and desiccated slime of the lake a fisherman finds a skeleton wearing a bag over its skull.

Paris, October 2011.

In an elegant apartment in Paris, forensic expert Enzo Macleod pores over the scant evidence of this, the sixth cold case he has been challenged to solve. In taking on this old and seemingly impossible task he will put everything and everyone he holds dear in a peril he could never have imagined.