Jonathan Anselme, a young scholar from England, joins forces with Max Böhm, a bird enthusiast, to track the migration of storks from Switzerland to Africa. Max is determined to uncover the mystery behind the birds that fail to return from their journey. However, when Max is discovered dead under suspicious circumstances, Jonathan embarks on the expedition alone, unaware that he will become entangled in a global conspiracy. As Swiss detective Dumaz delves into Max Böhm’s shadowy past, Jonathan is compelled to face his own troubled history. He follows a trail of gruesome murders through Bulgaria, Turkey, the Middle East, and the Congo, tracing the path of the migrating storks and their lethal secret.