Others have mentioned the old movie serials. The cover on my Alpha Video DVD claims that "The Shadow of the Eagle" is "The Complete Serial." But one part is missing in the early series, and it ends with episode 11 -- but not the end of the story. So, I have no idea how it comes out.
"The Shadow of the Eagle" is an early John Wayne series. It was a stunt man's show, with lots of action and running about. The Duke's acting is OK and very good in places. We can't say that for most of the rest of the cast – especially not Dorothy Gulliver. She has several close-ups in which she has hammy glares at the camera. Was she still acting for silent films?
The attempt to show sky-writing is pathetic. An airplane in the sky making 90-degree and 180-degree turns in just a few feet? It looked exactly like what it was – a toy model. I'm sure they could have done something to seem a little more real. By 1932, many people would have seen skywriting at daredevil shows, air shows, county fairs and other events held around the country. So, this probably would have looked just as hokey to audiences then, as it does today.
Although the plot was interesting, with just enough intrigue to keep one watching – hoping to see the end, it soon reached the point of tedium. The action scenes were repeated car chases, repeated climbing up and down outside buildings, and repeated breaking into the same offices. John Wayne must have had a permanent concussion from this one – I think he got conked out at least once in each segment.
The segments were of varied lengths. The shortest was less than 10 minutes and a couple early ones were half an hour or more. Each one ran the full credits at the beginning. But there was very little continuity between episodes. They tended to skip some details where the next episode would open somewhere off from where the previous one ended.
This Mascot production clearly shows its poverty row origins. It has very poor writing, editing and other production values; and the film quality relegates this one to the dust bin.