Columbia serials have a certain charm. This is no exception, with a story of someone going undercover as a "baddie" to gather intelligence. In this case, the hero also assumes a Secret Identity as the Black Commando, who, like to Green Hornet and others is viewed as a criminal, but is really on the side of Truth, Justice, and the American Way.At the end of each chapter, someone in an Army officer's uniform teaches elements of simple cryptology. Someone e-mailed me that there was a very clever method to conceal secret messages, and I pointed out that it was something that had been around for a long time, but not as general public knowledge. (For the curious, it was a Cardano Grille: a message is written so that when a mask is placed over a message only certain words -- the real message -- can be seen.) Almost any elementary book on cryptology has these, and other, examples of message concealment.Spoiler: Near the end of one chapter, a gas is introduced that is so poisonous that mere contact with it would prove fatal. Later, the Black Commando is exposed to the gas, and he collapses in a room at the close of the chapter. At the next episode's opening, he collapses, but then gets up, opens a window, and exits that way. Not quite a cheat, but close: either the gas wasn't like a nerve gas, or the Black Commando was superhuman.That aside, it was rather entertaining, and well above average for such fare.

Police Lieutenant Dan Barton stages a public dismissal from the police department, in order to join a band of Nazi agents/saboteurs and learn their secret code they have been using. To further assist his efforts, Barton assumes the identity of the Black Commando, who is wanted by the villains and police, who are also searching for Barton for a murder charge. So much great stuff happens in this serial. To begin with, Spencer Bennett's direction is some of the best of that field in serial history, with action a plenty and hardly any slow spots. Paul Kelly may have an annoying toughness to the role, but he carries his performance well. Great WWII example of how spies and saboteurs can be as close as the man you shake hands with. Also extra attraction of the code breaking segments at the end of each chapter. Rating, in terms of serials,- 10 of 10.