The Hidden River — Donald Willerton

A crazed professor is on a rampage to prove that horrible crimes were committed by the ancient ancestors of today's Pueblo Indians. His murderous accusations stir the community into anger and violence.

Vacationing nearby, Mogi Franklin and his family are suddenly caught up in the turmoil roiling the countryside. In this third book of the exciting Mogi Franklin Mysteries, the young hero must find a sacred object hidden by the ancient people of Acoma Pueblo somewhere in the vast, forbidding lava beds of western New Mexico.

To those who lived on the stark, high mesa four hundred years ago, it held a magic that could defeat the Spanish conquistadors despite their steel and steeds. To Mogi, it was an ancient mystery he must solve to stem the rising tide of bloodshed. But the clock is ticking, and his deranged adversary traps Mogi, Jennifer, and their friends in the absolute darkness of an underground cavern, with little hope of escape.