Tintin au pays de l'or noir
The next Tintin adventure was "The Black Island" (1937–1938), which saw the character travel to Britain to battle counterfeiters and introduced a new antagonist, the German Dr. Müller. Hergé followed this with "King Ottokar's Sceptre" (1938–1939), in which Tintin saves the fictional Eastern European country of Syldavia from being invaded by its expansionist neighbour, Borduria; the event was an anti-fascist satire of Nazi Germany's expansion into Austria and Czechoslovakia. In May 1939, Hergé moved to a new house in Watermael-Boitsfort, although following the German invasion of Poland, he was conscripted into the Belgian army and temporarily stationed in Herenthout. Demobbed within the month, he returned to Brussels and adopted a more explicit anti-German stance when beginning his next Tintin adventure, "Land of Black Gold", which was set in the Middle East and featured Dr. Müller sabotaging oil lines.