Isak is a tall, long-limbed Bavarian man whose stillness makes him seem to take up more space than his frame should allow. His wavy blond hair is flattened beneath a green felt hunting hat, then springs loose in damp curls. Grey eyes travel first to doors, windows, and the dark gaps beneath furniture; only then do they settle on a face. He moves with a logger's careful economy, placing each boot as if the ground might be trapped. His wolf-skin hangs from his shoulders like a heavy, tawny pelt, its coarse outer guard hairs rough against the smoother russet underfur. Unexpectedly, he keeps a tiny pressed-flower book tucked in his coat and handles it with the same solemn care as his rifle.

Methodical and observant, Isak can be patient with a difficult mechanism but impatient with a person who lies badly. He enjoys the pursuit and can become openly playful when a quarry proves clever, yet dislikes needless mess and keeps careful promises about payment. In public he is guarded and matter-of-fact; alone in the woods he is more animated, speaking to traps and animals as though they were coworkers. He is capable of tenderness toward the memory of his family but responds to living affection by changing the subject.

Isak grew up in a timber camp where his father taught him to judge a tree by its creak and his mother taught him to keep accounts of every favor owed. He became a logger, good with axes, pulleys, and the stubborn mechanisms of a sawmill. The work paid poorly, and when a foreman blamed Isak for a fatal rigging failure, Isak discovered that being feared could earn more than being dependable. He began taking night work as a hunter, first tracking wolves and poachers, then accepting discreet contracts against people who had vanished into the woods. The turning point came when he found a wolf-skin in a hollow beneath a felled beech, still warm though the beast it belonged to was long dead. He wore it in desperation to escape a winter pursuit and woke the next morning with blood on his teeth and no memory of the night. Rather than destroy it, he learned to use it. Now he hunts for the settlements around the tract locals call the Nettles, named for the weed that returns wherever anyone clears ground. He still sends part of his pay to his mother, Hedi, who believes he is a conventional gamekeeper. He avoids his former foreman, Jost, who knows the rigging accident was no accident and has begun asking questions. Isak's current trouble is a run of livestock killings that he did not commit: someone is imitating his wolf tracks, and the villagers are preparing to burn the forest edge.