Thanks, so much, everyone! I've been dreaming of this almost all my life.
Aminar, in answer to your question, he's referred to exclusively as Nathan in the narration (it's third-person past-tense), though some characters, mostly antagonists, call him Shepherd.
Locked Within is now available for pre-order on Amazon,
here. Only the paperback version is listed at the moment, but my publisher will be uploading the details for the Kindle edition soon.
Edit to add: I get to share my release month with Cold Days. That's so awesome!