Our interplanetary explorers from the Earth are coming to grips with a strange civilization on Mars. Pitting their strength and ingenuity against the terrible super-strength of another race, they show through page after page of this swift-moving tale that when interplanetary travel comes we must be prepared to meet it, no matter how strange or mysterious. Written by Wood Jackson, this story was published as a three-part serial beginning in the final issue of AIR WONDER STORIES in May 1930, and concluding in WONDER STORIES for June and July 1930, published by Hugo Gernsback through his Stellar Publishing Corporation.