Below: Nita Van Sloan (the luminous Iris Meredith) is the object of affection for Richard Wentworth (Warren Hull)

Iris Meredith made a beautiful Nita Van Sloan. Again the casting was perfect, not only did she resemble her magazine depictions, she captured the character's grace and courage. It was a shame that the writers couldn't also give her the grit and passion of the magazine stories, but this was a 30's kid's movie serial. She's a little too prone to scream simply because she's the woman in the film to truly be the Nita we know and love. (As a platonic ideal, of course, Mr. Wentworth …)

Kenneth Duncan as Ram Singh, shown at right perusing The Spider , played his part well, using a slight  British accent to differentiate the character from the others. (It was a better decision than to try an Indian accent - which can come off as silly or demeaning to modern audiences.) He and Wentworth are completely in character, with Ram praised as "Warrior" by his "Master". Ram Singh also displays his skill with a knife, which is somewhat surprising for a hero in a film intended primarily for children.

Richard Fiske plays Jackson, Wentworth's  aide (his first name was never used in either of the serials, to the best of my knowledge). He calls Wentworth "Major", as in the stories, but often seems a bit bemused by the proceedings. One interesting point is that the much leaner Fiske towered a good six inches over Hull, who was not particularly tall. Even so, Jackson is able to don The Spider's costume when Wentworth is accused of being The Spider after he is seen coming out of a dead-end culvert where he left another set of his mask and cloak.

Forbes Murray is fine as Commissioner Kirk, but doesn't have Kirkpatrick's military bearing or clipped mustache.

Donald Douglas as Jenkyns the butler is a much younger man (40-ish) than the elderly and sometimes befuddled family retainer depicted  in the magazine. This Jenkyns is a capable man in a fight, and is fully aware of Wentworth's role as The Spider.