The Graveyard Shift by Darynda Jones

From New York Times and USA Today bestselling author Darynda Jones comes a new story in her Charley Davidson series…

Guarding a precocious five-year-old who is half-human, half-god, and 100% destined to save the world is no easy feat.
Garrett Swopes was the ultimate skeptic until he met a certain hellion and her husband. They vanished after stopping a catastrophic event and left him, a mere mortal, in charge of protecting their gift to mankind. But when she disappears as well, he needs the help of another breed of hellion. One who can see past the veil of space and time. One who betrayed him.

She will get a truce in the deal, but she will never earn his forgiveness.
Marika Dubois’s son—a warrior in the coming war between heaven and hell—was foreseen long before his birth. But to create a child strong enough to endure the trials that lay ahead, she needed a descendant of powerful magics. She found that in Garrett Swopes and tricked him into fathering her son. A ploy he has never forgiven her for. But when he knocks on her door asking for her help, she sees the fierce attraction he tries to deny rise within him. And Marika has to decide if she dares risk her heart a second time to help the only man she’s ever loved.