"Lucky Starr and the Big Sun of Mercury" by Isaac Asimov (writing as Paul French), (Lucky Starr series, Book 4 of 6)

"Ghosts!" cried the engineer wildly, flinging his arms about. "I've seen them, but will anyone believe me?"

Bigman said, "Ghosts! Are you nuts?"

At once, Mindes screamed, "You don't believe me either. But I'll prove it."

With a harsh screech of laughter, he drew his blaster, and with frenzied speed, before Bigman could move to stop him, he aimed it at Lucky at point-blank range and squeezed the trigger ...

Can Bigman save Lucky before it's too late?

Written in the 1950s as a way to interest young people in science, the Lucky Starr series has delighted readers of all ages for decades. 

This copy was printed by Fawcett in 1978 and is in good vintage condition.