Forging Darkness by Julie Hall

No one knows if Steel is dead or alive… except me.

For months I kept the late night calls from Steel a secret, until he let it slip that he tracked down his villainous sister, Silver. He needs help—even if the powerful angel-shifter is too stubborn to admit it.
But the Steel I find isn’t the same boy from Seraph Academy. He’s darker. Haunted. And the distance between us can’t be crossed by a simple flap of my wings.

When a battle with the Forsaken goes horribly wrong, I awaken as a prisoner inside a Fallen stronghold. My enigmatic abductor—Thorne—is manipulative, secretive, and claiming I’m meant to rule by his side.
I’m not buying it, especially since the alluring offer to unveil the mystery of my seraph ancestry comes at the cost of bringing every Nephilim to their knees.

Lines between the realms will blur. My world will burn. And this time, I’m not sure I can fight the darkness on my own…