It is prior to the American entry into World War II, and Japan's fiendish Black Dragon Society is hatching an evil plot with the Nazis. They instruct a brilliant scientist, Dr. Melcher, to travel to Japan on a secret mission. There he operates on six Japanese conspirators, transforming them to resemble six American leaders. The actual leaders are murdered and replaced with their likenesses. Dr. Melcher is condemned to a lifetime of imprisonment so the secret may die with him.

https://www.youtube.com/watch?v=bB_EaICz2EE
[Public Domain?]