I honestly haven't loved every single book I have read, but Kallysten delivers another 5 for me.  I think the one thing that stood out to me the most was the relationship between Marc and Blake.  The Sire/Childe bond is so very strong, but even it can be blurred.  Marc and Blake end up helping Kate, a human fighter, and the group of rebels she belongs with, fight against demons that are coming into their world. Kate feels a pull to both men and in her own way tries to not come between them, even as they try to put her there.  Everyone has their own reason for fighting, duty, honor, fun and it takes all of them, even the most scared and timid to fight and send the Demons back where they came from.  In the end, betrayal is seen as the catalyst to the demons coming and to the destruction of the Sire/Childe bond.  This bond will either be made stronger, or will be lost.  I will patiently wait for the next installment.