Low Lords — T.R. Pearson

Eighteen-year-old Hoyt MacKenna was born into a secret society. He's a Low Lord, a cave minder, and his job is to keep what's under down, but what's under has teeth and savage intent and would far rather be up in the world. Tough duty for a teen with a glorified bush axe, a headlamp, and an itch to be somewhere else.