Enchantment's Trap - Vampire Magic, #4

The Vampire Prince risks it all in the war with the Fae. Callie discovers untold powers, connects with her past, and transforms in a way she never expected. The rescue of her sister teeters in the balance. A centuries-old sorceress, vampire magic, and a horrifying blood exchange thrust her into a new state and unexpected consequences. Logan taps into his supernatural abilities to save Callie and her sister.
Yet he meets with forces more powerful than anticipated. A life-changing event releases his strength as never before. The prince must save the woman he loves, and the very world he lives in.