Switzerland 1523. The mercenary Hansli Gyr returns with his soldiers from Italy to his home in the Oberland. They have fought for the Pope and now find a religious upheaval in Switzerland.

Sebastien Grenier, a former French spy, is working as a financial analyst in Zurich. However, his peaceful existence starts to disintegrate when he is recruited by a top French intelligence operative to discover how one of their own secret agents was found out and executed in broad daylight.