Der Wächter der Quelle.

Having risen to the rank of investigator within a special commission of the Ministry of the Interior—an agency operating throughout Austria—Moritz Eisner is summoned to the Tyrolean village of Steinbach to solve a particularly difficult case alongside his Tyrolean colleague, Barbara Trenkwalder. Environmental activist Hermann Wegschneider—who had been a thorn in the side of many in the village due to his bitter struggle against the industrial exploitation of a local healing spring—has been found dead at the spring itself.