An excerpt from Tamper by Bill Ectric:
“Like their souls, you mean?”
“Call it what you will,” I said. “The fact is that people still hear noises in the catacombs of Malta, even in these modern times.”
“Ahhh, Malta,” said the shrink. “We found that old National Geographic article folded up in your diary. About the school children and their teacher, getting lost in the underground tunnels on the island of Malta.”
“Yes, it was a page from a 1940 issue of National Geographic that we found in the envelope that Glenda Wells dropped in Olsen Archer’s house.
Another excerpt from Tamper:
In the 1940s, Richard Shaver sent a story to the magazine about a race of evil mutants, called Dero, who lived in underground caverns and sometimes captured humans to torture and eat. According to Shaver, the Dero were descended from aliens who got abandoned on Earth in ancient times. The aliens landed here but found Earth’s sun dangerously hot to their metabolisms. Most of them abandoned Earth and departed in their spacecraft. A few had taken shelter in caverns to avoid the heat and were left behind, either accidentally or on purpose by their alien squadron. Centuries of inbreeding underground had made them insane and sadistic. Shaver also claimed that the Dero were using some kind of energy beam to send disturbing voices into his own mind. He called this mental harassment “tamper.”
Thanks to Richard Toronto for his book on Richard Shaver and Ray Palmer, War Over Lemuria