Louis Antioch, a young scientist-philosopher, receives a strange offer from the friend of his adoptive parents: the famous Swiss ornithologist Böhme. He asks Louis to follow the migration route of storks and try to find out why several hundred ringed birds never returned to Europe to their native nests. The day before Louis is set to leave, he finds Böhme dead. The circumstances of the ornithologist’s death seem suspicious to him, and he decides—whatever happens—to carry out the planned journey. Not even a few days pass before Louis realizes that his trip is a very risky undertaking.