Bordeaux, April 2013. Two deaths in suspicious circumstances lead police captains Alex Nowak and Olivia Sudret into an investigation full of unforeseen developments. A determined and Machiavellian killer has developed an ingenious watchmaking technique in order to attain his evil ends. Against a background of racial hatred and with flashbacks into the past, the intrepid investigators refuse to give up. They can have no idea, however, that their enquiries will lead them across borders as they try to follow the traces of a story from the past which would have been better forgotten....