Balthus is an young man, recently sent to help defend the border lands of western Aquilonia; lands which encroach upon the territory of the savage Picts. He meets and befriends Conan, a Cimmerian, who has been serving at the nearby fort as a tracker and soldier for several months. There have been a recent rash of murders, perpetrated by demonic minions of Zothar Sag, a Pictish chieftain. Conan suggests breaking the shaky peace with the Picts in order to put a permanent end to the problem. He assembles a small team, including Balthus, who along with himself, will sneak into Zothar Sag's camp and kill him. However, this will require them to cross the Black River and into Pictish territory, a savage land for a savage people, populated by all manner of beasts, and some things out of their nightmares.
Often considered one of Robert E. Howard's greatest works, it features many of the recurring themes present in his other works, such as the man's inmate barbarism and the impermanence of civilization, yet given far more focus here.
- A Boy and His X: Balthus and Slasher.
- Alone in a Crowd: Balthus feels alone in Conan's presence.
- Author Avatar: Balthus, according to Howard himself.
- Bring News Back: What Conan and Balthus try to do.
- Deus Exit Machina: Conan and Balthus separate near the end of the story, mainly so Conan can have a fight with a forest demon while Balthus defends the escaping settlers in a Heroic Sacrifice.
- Distressed Dude: Balthus, one of the few male examples in a Conan story. He changes pretty quick.
- Friend or Foe: Conan deludes a Pict.
- Half-Human Hybrid: Zothar Sag is half swamp demon.
- Heroic Sacrifice: Balthus and the dog.
- Human Sacrifice: Part of the Ritual Magic.
- Jungle Drums: The Picts use them.
- Libation for the Dead: Conan at the end.
- The Lost Woods: The Pictish wilderness definitely counts, as does the border lands the settlers call home, to a lesser extent.
- The Natives Are Restless: Picts.
- Panthera Awesome: A saber-toothed tiger! Even Conan is shocked that one is still alive. Later an actual jaguar tracks the heroes through the forest.
- Power Glows: The forest demon, who glows green.
- Ritual Magic: The Picts practice it.
- Scarily Competent Tracker: The Picts, to the point where despite traveling tens of miles through the forest, Conan tells Balthus it's only a matter of time until the Picts find them.
- To Absent Friends: Conan and some woodsmen discuss the settlers and the people who died at the fort over drinks at the end of the story.
- Would Not Shoot a Civilian: Dead civilians enrage Balthus.