Drawn to Darkness: Complete five book series

The small hole was waiting, inviting anything or anyone to enter, lacking the glamor of other caves in the area, with big entrances decorated with formations, this hole only offered peace and quiet for whoever ventured to enter. This small hole slowly drew Matthew and his friends closer, curious about what was inside, beyond the darkness, with cool air gently moving the weeds near its opening, to explore the secrets hidden within the mountain.

Matthew, Clair, John, and Joann had grown close in the small Tennessee town, playing along with the mountain and the river that flowed into the nearby lake. When they found a small rock with a pictograph of an Indian carrying something strange they set off on a quest to solve the mystery of what may be hidden in a cave along the Piney River.

Ed, a hermit who lived on the mountain had found some Indian relics and believing for years they had hidden gold somewhere in the area, spent his life searching for it. He became suspicious of the kids playing nearby and was afraid they would find it first.