Mark of The Night. Servants of Morrigan: Four Horsemen

One life is all most mortals have. So what exactly is one life worth? Before Grace Gillingham was kidnapped out of the twenty-first century, the mortal thief would never have dared to attempt to outwit Death. But that's exactly what she must do to save her brother. Once her brother is free, there is nothing that will stop her from destroying the criminal organization that stranded her in antiquity-even if it means being hunted by the Four Horsemen. Burned once by the fates, the Commander of the Four Horsemen, Dante Giovanni, disregards a prophecy claiming that he is destined to a woman bearing the mark of the night.
But when Grace steals an ancient relic he is sworn to protect, their fates become irrevocably intertwined. Dante soon realizes Grace is merely an innocent pawn. Even so, he's under orders to protect the realms and apprehend her. If he spares Grace, he risks putting all living beings in danger. If he condemns the fiery mortal, his conscience will forever haunt him. Damned if he does and damned if he doesn't, what's Death to do?  Until this moral conundrum, Dante believed he understood the worth of a human life.
But that was before he met the woman he'd risk his soul to save. Mark of the Night is Book One in the Servants of Morrigan: Four Horsemen series, a historical epic fantasy filled with romance, action, and intrigue that spans time and the Mediterranean world.