With the hope for a feral cure now lost—due to the death of Dr. Jack Tanner—Major Rathbone, Salvatore, and Rebecka Hayes set off for the werecat and human safehold in the Olympic Mountains. Along the way, they hope to recover the rabid sisters Pippa Reyes and Abby Hunter as they make their escape across the feral-infested wastelands. But following a bizarre twist of events, we find that both Jack Tanner and Aiden are still alive. Dr. Tanner is given a second chance at life when he evolves into a half-bat, half-marsupial creature known as a nocturnal. After dealing with his own demons, which threaten to make him as rabid as the sisters who hold the key to saving the world, can the doctor reunite with Abby and Pippa, and find a cure before the growing feral infestation consumes what's left of humanity?