There is no such thing as a lone wolf.
Diedrich Koch thought he was safe in the secluded Colorado woods. After escaping a string of gruesome murders in the city—and the terrifying, naked "sleepwalking" episodes that followed—solitude was supposed to be his sanctuary. But the forest isn't empty, and the moon brings a fresh layer of blood under his fingernails that he cannot explain.
When a group of hikers arrives at his cabin looking for a missing friend, Diedrich realizes the nightmare he tried to outrun has followed him into the mountains. The four pink scars on his neck aren't just remnants of a forgotten attack; they are a beacon for something far older and more dangerous than any beast.
As an ancient predator named Luther closes in, Diedrich is forced to confront a bloodline he never knew existed. With his partner Archer and his estranged father at his side, he must navigate a war between two worlds. To protect those he loves, Diedrich must learn to control the wildness in his veins before the "Fallen" claims its next host. He woke up with a mark—now he has to choose: join the pack or be hunted to extinction.