From Burning Ashes (Collector #4)

This war is not being played on a battlefield.

Killed by the man she loves, not even death is kind to Zoey.
Neither life nor her fae powers will let her go in peace.

In this final installment, Zoey’s strength, determination, and trust are put to the ultimate test. In the fight to protect the people she loves and stop DMG from experimenting on fae, humans, and animals to create soldiers, she learns the reality of how far Dr. Rapava will go to achieve his ultimate mission.

Of course, Rapava is not the only one willing to go to extremes. Vadik is hunting Ryker, and there is nothing he won’t do to get back the property he feels is his: both Ryker and the Stone of Destiny.

To end one evil, Zoey might have to make a deal with another. One she won't be able to get out of. And it could be the worst decision she ever made.