Captain America does battle with a supervillain known as The Scarab, who is killing off all members of a Mayan expedition.
You know, if you're going to fight crime while wearing a silly costume you should either a) have superpowers, or b) have a truckload of useful gadgets, or at the very least, c) be a Mexican wrestler. If you can't manage any of these things, at least you should be phenomenally competent, and I'm afraid that's the category that Captain America falls into in this serial. I'm really not familiar with the Captain America of the forties, but from all reports, this guy is a pale imitation of him. However, he is very competent indeed, and (this being a Republic serial), the fights are exciting and well staged. The cliffhangers are better than usual as well, though they do get a little repetitive and eventually rely too much on certain standard perils. This serial also has the presence of Lionel Atwill, who makes a formidable foe indeed. All in all, I found it one of the more enjoyable serials I've seen, but I would warn any fans of the real Captain America to expect somebody other than the beshielded hero they know and love.