Agartha. Sedona Series, #3

Agartha a journey into middle earth and the new Atlantis (alternate history), Second chance and redemption. Opposites in every way, but love casts a spell on them stronger than magic. On a mission to request help from the community of Zorith, April Lopez travels to Middle Earth, a subterranean world that may know how to prevent an evil dark fae with her sights set on Arizona from turning humans into mindless thralls. But the psychic visionary runs into a bigger problem days after her arrival: haunting visions of a past life she never knew of before.
Desperate for answers, she turns to the Zorith's leader, Sarielle. April can't deny the sizzling chemistry they have together, but Sarielle is an Atlantean, reserved and cautious where she is open and headstrong. Convincing him to risk his people for hers may be an impossible task. Sarielle Torian serves as an Atlantean priest, and with that position comes the grave responsibility of safeguarding Zorith.
He wants no part of a war between the fae and humans. Now a strange human woman has traveled to Sarielle's land, asking for aid. April occupies his thoughts, kindling a fire between them that he can't easily extinguish. He doesn't want to refuse her, but is he supposed to sacrifice Zorith's future for a slim chance at victory? When a locket April wears turns out to be a relic containing an encrypted message, Sarielle hopes that it will provide answers to April's visions and his dilemma.
Because no matter his loyalties to his home, he doesn't want to let April go. Agartha is the third book in a fish out of water time travel portal fantasy romance set in a world where middle earth must help humanity rise to their highest potential.