Haunted by the Keres (Book Four of The Shape Shifter Chronicles) by Lauren Jankowski
A brutal attack on the rebel Lair signifies an escalation in the war against Grenich. The guardians’ strict policy of neutrality means the shape shifters must reforge old alliances with other species. However, the blood feuds between the two different species are not easily forgotten.
Meanwhile, the Four try to figure out a way to strike at Set. A question looms over them: can experiments learn how to be protectors, even when it goes against all their instincts? The answer could determine the outcome of the war against Grenich.