Simone. Of Blood & Dreams, #8

The Dagger of OmarA symbol that once united vampire and dreamwalkerSimone, loyal cadre to House Trelane, has never trusted dreamwalkers-especially not Colantha, a woman who wears her power like a crown and hides her secrets behind royal smiles. But when Colantha speaks of the Dagger of Omar, a relic once said to unite vampire and dreamwalker, Simone's world tilts into chaos. She's seen that dagger before.
In the hands of Gaius-her former lover and eternal tormentor. Now Gaius has vanished, and whispers of the dagger's reappearance have stirred ancient enemies. To save him-and perhaps herself-Simone must walk a dangerous path between betrayal and desire, uncovering a truth that could ignite another war. or end both their worlds forever.