Lloyd Bridges only movie serial, Secret Agent X-9, also featured two actors who played Charlie Chan’s sons in that popular movie series, Key Luke and Benson Fong. Going after a synthetic fuel formula provides the motivation for thirteen chapters of action and cliff hangers. Universal was unique with their serials by not providing the traditional chapter recap of the story so far. Instead, they had characters in a following chapter recap, through their dialog, what transpired in the previous chapter (as noted in Gripping Chapters: The Sound Movie Serial, by Ron Backer, BearManor Media). Universal did a Secret Agent X-9 serial in 1937 too. That storyline centered around stolen jewels. Both serials were based on the comic strip character of the same name written by Dashiell Hammett and drawn by Alex Raymond.