Stalked By Shadows by Lissa Kasey

A missing girl, ritual murders, and a shadow stalking every footstep.

Alexis Caine survived an attack in the deserts of Afghanistan. An attack the government denied and discharged him for, leaving him broken and in a mental institution. What Alex saw that day in the desert continues to haunt him.
When a new job working as a bodyguard for a New Orleans ghost tour guide, Micah Richards, opens Alex’s eyes to a world of paranormal possibilities, he’s not sure he can believe his eyes. What if he’s not crazy after all? When a ritual murder in which two fellow tour guides die and a tourist vanishes, Alex wonders if he brought a curse down upon them all.
A shadow from the desert rears its nightmarish head offering Alex something he wants more than anything, but at what cost?