Typically exciting Republic serial, with Ralph Byrd, who went on to a career as Dick Tracy, in stalwart form with an unlimited supply of dress uniforms: in every chapter he's either dirtied, soaked, or blown up, but he always comes back conforming to regulations. Lugosi is evil scientist with a gas that disintegrates almost everything. Some great (and some laughable) special effects from the Lydecker brothers, gaining experience that would make them tops in the field in coming years.