Hazel Hunter - The Hollow City Coven Series [Book 1-4]

Possessed (The Hollow City Coven #1)
A daring quest. A lethal enemy. A protector who won’t quit.
Although Wiccan Gillian Granger’s life’s work is finding a legendary city, her research in musty libraries hasn’t prepared her for fieldwork. Add a gorgeous escort, and she is completely out of her depth.
Shayne Savatier knows he’s on a milk run, especially after he meets his beautiful charge. But when enemies attack her, everything changes. The mission turns deadly, passion intertwines with protection, and duty bonds hard with desire.

Shadowed (The Hollow City Coven #2)
A frightful destination. A love that is destined. A fight to stay together.
As Gillian and Shayne embark on the next step of their journey, it takes an unexpected turn. Aboard a ship with an eerie captain and strange first mate, their passionate new relationship is put to the test. But finally making landfall at the fabled Midnight Market only compounds their troubles.
As Gillian searches desperately for the means to continue her quest, Shayne struggles to protect her. Though she’s pursued and seized at every turn, her own obsession is her undoing. In the Midnight Market there is only one law: everything is for sale. Everything.

Trapped (The Hollow City Coven #3)
A lover from the past. A dream remembered. A sensual awakening.
As Gillian approaches her goal, it only becomes more elusive. Near the legendary city of Tenebris, attackers in the remote wilderness of Cappadocia will stop at nothing to see her fail. Though she and Shayne have help, their new companion is a complication.
As different from Shayne as could be, the mercurial Mathias is a breath of fresh air. Though he and Shayne have a history, he makes no excuses about his desire for Gillian. But for her part, Gillian senses more than just attraction. She and Mathias walk in footsteps that they’ve somehow trod before. But the strange déjà vu is not the worst part. Their dim memories mix with vivid dreams, and in those dreams she dies.

Haunted (The Hollow City Coven #4)
An undead city. An ill-fated love. A nightmare relived.
Wiccan researcher Gillian Granger can hardly believe she's reached her life's goal, but the accomplishment is tempered. The ancient city of Tenebris holds as many terrors as it does wonders. As she and Shayne wander its ghostly streets, Gillian must finally admit she's been there before. But as the bond between her and Shayne grows ever deeper, they find that the city's claim on him is just as strong. Though Gillian had once dreamed of finding the Hollow City, now she'll do anything to escape.