Guardian of the Dark Paths by Susan Trombley

Sarah had many doubts about entering an abandoned mine to help her best friend capture video footage to share on her social media. Convinced to do it anyway, her worst fears are realized when the exploration quickly goes awry, plunging Sarah into grave danger. Separated from the group and isolated in the depths of a long-forgotten mine, she must hold onto her wits and her sanity to survive, because something nightmarish hunts her through the darkness. Her only option is to travel deeper to escape it.

Jotaha serves as the Guardian of the Dark Paths, patrolling deep underground in a maze of tunnels and caves that protect his people from human invaders. His duty is to kill any human who crosses the boundary into yan-kanat territory, and he performs that duty admirably.

Until he meets the one human who is destined to be his mate.

They are from two different worlds that have clashed violently in the past. Humans view reptilians as monsters straight out of myth and urban legend, and Jotaha’s people view humans as their mortal enemies. Will the decree of a fertility goddess be enough to convince the yan-kanat that Sarah belongs with their guardian? Or will the enmity that exists between their people end up destroying the growing love between Sarah and her reptilian mate?