Dangerous Game by Zane Michaelson

After the shock discovery of Adriel’s true nature, Sebastián and Sienna whisk her away to Venice in the hope of tracking down Millicent Balanza.
A powerful witch in her own right, Millicent, is a direct descendent of Sienna, and Adriel’s only hope.
Wary of her own gifts, Millicent has retreated from the real world and lives a solitary existence. She hasn’t spoken to another living soul for many years, but this could change as she senses Sienna’s presence.
Will Millicent reveal herself to Sienna?
Is she powerful enough to protect Adriel?
Only time will tell.
Back in London, leader of the vampires, Zahir, is on the hunt for Sebastián and Sienna, hell bent on making them answer for their crimes.
Following the death of Lucy, Zahir will leave no stone unturned until he finds out why she was murdered by Sebastián, and why Sienna conspired to cover up the crime.
Desperate for answers, he tracks down Adriel’s ex-lover, Benjamin, who has been compelled by Sebastián to forget the events of the last few days.
Now, only Benjamin’s blood will reveal the truth.
Will Zahir discover what Adriel is?
What will the discovery mean for them all?