Tom Corbett, Space Cadet #3

When Tom Corbett and his fellow cadets arrive on Mars for what seems like a well-deserved furlough, they learn their vacation is actually a covert mission: Lance Sterling, a renowned pilot and father of Tom's old friend Terry, has been blamed for crashing a secret transport ship and has since become a drifter on the lawless moon Deimos. Tom and his crew discover that saboteur Mark Selgar—a smuggler Lance once helped imprison—is suspected of wrecking the ship and is now determined to keep Sterling broken and hopeless. The cadets must venture into the dangerous Meteorite bar on Deimos to locate Lance and uncover the truth before Selgar makes good on his revenge.

Captain Quick and the Space Scouts venture to Callisto searching for signs of life, only to discover an ancient spacecraft hidden beneath the planet's overgrown forest—and its missing crew, led by Commander Lucius Roberts, who abandoned Earth twenty years ago to build a peaceful paradise. When Captain Quick learns the truth about the long-lost expedition, he must decide whether to report his discovery or honor the hermits' desire to remain undisturbed on their adopted world.

When a desperate distress call reaches Captain Strong reporting Doctor Warren missing on Mercury's volcanic surface, Tom Corbett and his fellow cadets race to the planet's sun-scorched craters to mount a rescue—only to discover that hostile forces from Mercury's dark side have taken the doctor and his granddaughter captive. The cadets must navigate treacherous lava tunnels, outsmart alien warriors, and race against an erupting volcano to save the Warrens from a sinister ritual.