The Magician of Mars, a 1941 novel written by Edmond Hamilton

The Magician of Mars (1941), a science fiction novel by Edmond Hamilton.

Pictured: Paperback (New York: Popular Books, 1968) #60-2450, 128 p., 60¢, Cover art by Herbert J. Bruck. Here is the promotional piece from the back cover:

His real name is Ul Quorn, but he is known throughout the Solar System as the Magician of Mars. With sheer scientific mastery and cunning he once terrorized the entire population of all nine planets -- until Captain Future put an end to his evil deeds. Now Ul Quorn has broken loose from the escape-proof Interplanetary Prison -- a feat that was believed impossible. His plan to obtain wealth and power is more ingenious than ever before and more deadly to the System. Soon he will be master of the Universe. But first he must settle a score with Captain Future...

The Magician of Mars was originally published as a complete novel in the Summer 1941 issue of Captain Future.