The World Below by Mike Phillips

In ancient times, magical creatures inhabited the earth. They lived on mountaintops, in trees, at the bottom of lakes and rivers. But that was long ago, before the human race declared war on the creatures they feared and hated. Now the enchanted peoples are all but gone. Those few that remain fear being stretched out on an examination table in some secret, governmental facility. The only place they can hide from the ever increasing number of satellites and smart phones is in the World Below.
Mitch Hardy is going through a hard time in his life. In his early twenties, he was working his way through college when he suffered an accident that left him flat broke and physically deformed. When Mitch decides to make a fresh start in a new town, things start looking up. He finds a place to live, a decent job, good friends. He even meets a nice girl. Unknown to Mitch, his new girlfriend is one of the Elder Race, what some call the Faerie Folk. Mitch doesn’t know that Elizabeth is looking for a father she never knew. The key to finding him is somehow tied up with the mysterious Blade of Caro. Desperate, she steals the Blade from its protector, the despotic ruler of the World Below, the Dragon of Worms, Baron Finkbeiner. When Elizabeth is kidnapped by the Baron, Mitch is pulled into a world or magic and monsters he never imagined.