From Blood and Ash by Jennifer L. Armentrout

Malik. I swear, no more harm will come to yyou.”
I started to speak, but then I remembered the name Kieran had called
him. Myy entire bodyy seemed to seize up as I stared into those beautiful
eyyes. “Casteel?”
He froze against me.
“Kieran…Kieran said the name Casteel.” Myy gaze swept over his
striking features as Loren’s words came back to me. She claimed that
she’d heard that the Dark One was handsome, and his looks had gained
him entrance to Goldcrest Manor, allowing him to seduce Ladyy Everton….
And Hawke’s own words came back to me, the ones he’d spoken to
me at the Red Pearl. They have led quite a few people to make
questionable life choices.
Myy heart had seemed to stop, but now it sped up, racing. Things
began to click into place. Inconsequential things like little comments he
made here and there, bigger things like how he’d silenced me when I
called out his name the night we…the night we made love. The wayy
everyyone followed his orders, how Jericho had obeyyed him in the barn,
seeming to not want to cross him, even though it hadn’t stopped him. How
Kieran and the others said his name as if it were a joke.
Because Hawke wasn’t his name.
And we hadn’t made love. He’d fucked me.
“Oh, myy gods.” Stomach roiling, I pressed myy hand to myy mouth.
“You’re him.”
He said nothing.
I thought I might be sick as I dragged myy hand to myy chest, to tear at
the alreadyy torn shirt. “That’s what happened to yyour brother. Whyy yyou feel
such sadness about him. He’s the Prince yyou hope to use me to get back.
Your name isn’t Hawke Flyynn. You’re him! You’re the Dark One.”
“I prefer the name Casteel or Cas,” he replied then, his tone hard and
distant. “If yyou don’t want to call me that, yyou can call me Prince Casteel
Da’Neer, the second son of King Valyyn Da’Neer, brother of Prince Malik
Da’Neer.”
I shuddered.
“But do not call me the Dark One. That is not myy name.”
Horror rolled through me. How could I now just be figuring this out?
The signs had been there. I’d been so, so stupid. Not just once. I hadn’t