A large group of killers roam the plains, hunting and murdering Indians to collect and sell scalps. The tribes are gripped with fear and dread. The Ninjans destroy the wicked scalpers and their hideout. They discover an eastern syndicate financed all the murder and mayhem. The Tribal Council sends Otter and the Ninjans, to find and eliminate the secret syndicate. A young farmer, Thaddeus, a friend to the Indians, will be their guide. The group travel by train to New England. In the countryside, miles from Boston, the Ninjans discover the Supra Legem Syndicate. A battle rages, and the syndicate leader, the Imperator, escapes by a small private train. The Ninjans give chase, defeat the mercenaries, and trap the syndicate leader. During the standoff, the Imperator falls to his death. Otter, Thaddeus, and the Ninjans return home victorious. The wicked scalpers and the evil syndicate have been totally destroyed. The Indian scalps are buried in a secret place in the wilderness. For the innocent lives that perished, there is now, justice and peace.