What does an enterprising inventor do to follow up the marvelous dirigible-ship Monarch and an amazing submarine called Porpoise? Why, cobble them together into an astounding vessel that travels on both air and sea, and then head straight into his wildest adventure yet -... more »- more than twenty thousand leagues under the Earth! Along for the ride are his companions from the previous two Great Marvel books, teenagers Mark Sampson and Jack Sparrow, and the irrepressible Washington White. Lost race of giants? Killer plants? Deadly, bizarre creatures? Treasure beyond imaging? You bet. Long before Edgar Rice Burroughs headed for the Center of the Earth, Roy Rockwood (here, Howard Garis, author of the immortal Uncle Wiggly series) staked claim there with an adventure for boys that still might have Jules Verne spinning in his futuristic automated grave! Classic action-adventure science fiction at its best.« less