Mysteries of Unexplored Worlds #13

Dr. John Darrell and his assistant Rick Royce become the first explorers to land on Mercury, only to discover the planet's surface teems with enormous insectoid life—and something far larger lurks beneath, systematically hunting them. When their ship becomes trapped and pulled into the planet's depths, the two men must uncover the shocking truth about Mercury's nature before it's too late. A pulse-pounding 1959 sci-fi tale that turns everything we thought we knew about our solar system inside out.

Doherty, a government agent posing as the gardener for the eccentric Joshua Peel, discovers that his employer uses a powerful telescope to harness rejuvenating energy from a mysterious green star called Karu—a star that official astronomers insist doesn't exist. When Peel realizes Doherty has stumbled onto his alien connection and threatens to expose him, the agent must act fast to prevent Peel from being transported across space to the beings controlling the green star.

Professor Harold Dennis joins an iceberg patrol expedition, curious to witness the mysterious underwater disturbances the crew has been reporting near the glacial fragments. When the ship's demolition team prepares to blast an iceberg, the water grows unnaturally warm and turbulent—phenomena that perplex even the seasoned captain. The professor's quest to understand nature's peculiar behavior leads to a revelation about what the iceberg truly is.