Explorers on the Moon
"King Ottokar's Sceptre" introduced the recurring character of Bianca Castafiore to the series, who appears alongside her pianist Igor Wagner. It also witnessed the introduction of antagonist Colonel Jorgen, who reappears in the later Tintin adventures "Destination Moon" and its sequel "Explorers on the Moon". The Alembick brothers' inclusion echoes the Balthazar brothers' inclusion in "The Broken Ear".