The Tunnels of Yog-sothoth - Justin H Guess - Bog

After Victor gets abandoned behind enemy lines in Dives Valley, France, during World War II, he discovers the silver key and is transported to a mysterious realm. With the help of one of the denizens, Hodam, and Leo, a cowboy outlaw from Texas, he must travel through the 13 spheres of Yog-sothoth to find his way back to their world before falling prey to the horrors inside the many cyclopean tunnels.