I recently finished watching this 15-chapter serial. Silly and repetitive, as are most serials. However, typical of Republic, it had excellent special effects (courtesy of the Lydecker Brothers) and fight scenes. And sci-fi movies were quite rare in 1945. Linda Stirling was a popular serial heroine at the time (though she mad much less to do than in ZORRO'S BLACK WHIP the previous year). And I thoroughly enjoyed top-billed Dennis Moore as the hero (remembered fondly for his genre appearances in SPOOKS RUN WILD, THE MUMMY'S CURSE and (unbilled) THE FROZEN GHOST). Moore was handsome and short but scrappy, with an excellent voice. He mainly appeared in Poverty Row B-westerns. He died in obscurity in 1964.