Complex sentence: So he came upon the idea of doing a two-person mind-reading act, concocting a silly story about how his son Emile had created a game of hot and cold that resulted in Robert-Houdin using it for the stage.
Split into simpler sentences: So he came upon the idea of doing a two-person mind-reading act. He even concocted a silly story on how his son Emile created a game of hot and cold that resulted into Robert-Houdin utilizing that for the stage.