Old gold-digger Boston Joe finds the treasure of three unscrupulous criminals and they kill him for it. But before he dies, he confess to Zagor where he hid the treasure, and asks him to find his nephew Robert, who was kidnapped by Indians ten years ago. And so Zagor, after sorting out the situation with the treasure, will go in search of the boy and the Fox tribe, who fell into the arms dealers' trap!
This story can be divided into two parts:
First part of the story deals with the narrative line of the search for treasure and the conflict with three criminals.
Second part of the story is tied to the first part only by Zagor's promise to Boston Joe. The main actors, or villains, are two arms dealers, Harry Watson and his rough assistant Bryan. Unscrupulous traffickers duped Indians, convincing the warriors to barter the prized buffalo skins with the guns they stole from the Army.
After they saved the Indian tribe of the Fox from the schemes of ruthless traffickers, Zagor and Cico go back to their refuge in Darkwood. Here, a pair of criminals are planning to steal an Army wagon full of gold. Their diabolical plan is to recruit Olaf Botegosky, a strong man with an uncanny resemblance to Zagor. Disguised as our hero, Olaf will take his place and lead the valuable wagon trail into an ambush, putting the blame on the Spirit-with-the-Hatchet…
