After surviving the horrors beneath the frozen forests of the Ardennes, Lieutenant Declan Caine and his Hunters know the creatures unleashed at Bastogne were no isolated experiment. Somewhere inside Germany, the architects of the nightmare are still working-and they are getting better at what they do.
Now General George S. Patton has another mission for them.
Deep within the Black Forest, an American convoy has been slaughtered. The evidence points to something the Hunters have seen before, but the attack is different. More organized. More deliberate. Whatever the enemy is creating has begun to learn.
Following the trail into Germany, Declan, Rhiordan, Jed, and Doc uncover a hidden Black Sun installation where Nazi scientists have pushed their experiments beyond anything the Hunters imagined. Werewolves are being refined into weapons. Ancient secrets are being dragged into the light. And somewhere beneath the facility, the Germans have imprisoned something they were never powerful enough to control.
Something old enough to remember Rome.
Something even the monsters fear.
With Patton's forces closing in and the Third Reich determined to preserve its darkest research, the Hunters must tear the Black Sun apart before its horrors can escape into a world already drowning in war.
But some cages were never meant to hold what was inside them.
And in the Black Forest, the Hunt is changing.
The war is almost over.
The darkness is just beginning.