The 12-episode Universal serial The Adventures of Smilin' Jack is based on the Zack Mosely comic strip of the same name. The title character-minus his trademarked pencil moustache-is played by Tom Brown. Departing radically from the characters and situations of the original funny-paper version, the serial concerns itself with an effort by the Axis powers to find a secret route from India to China known only by the rulers of the (apocryphal) city of Mandon. Sidney Toler, then concurrently starring in the Charlie Chan series, plays a ruthless Asian general, while future Make Room for Daddy star Marjorie Lord is the plucky heroine. The serial's highlight sequence has Our Hero proving his mettle by walking barefoot over a pit of hot coals.