Vampire in Atlantis — Alyssa Day

The most unexpected of all allies to Poseidon's warriors has proven to be the fiercest-Daniel, a vampire and Night Guild mage. But even the strongest alliance can be destroyed when a vampire's oath crosses paths with a maiden's quest, and an eleven-thousand-year-old desire is reborn.

Ready to face the dawn and die after 11,000 years as a vampire, Daniel walks into the Reflecting Pool on the Washington Mall and ends up in Atlantis, at the mercy of Serai, a long-dead warrior princess he could never forget.

Yet Serai is not dead. Centuries earlier she and several others had been magically put into suspended animation to ensure the continuation of the Atlanteans. But the magical jewel that keeps them safe has been stolen, and, now awake, Serai must find it to save the other sleeping women.

Together, Daniel and Serai search for the stone and renew their relationship, stalked by an evil that isn't about to let them succeed.