Fifty feet further out, in a rough semicircle, lay another six Indians – younger men and boys, less skilled at hiding, and trailing, and killing, proud to be in the company of the two leaders and eager to learn from them. The youngest, and perhaps the most eager of all, Matsiguenga’s nephew Shako, was not yet twelve.

In La Cosa Nostra, the two leaders, Matsiguenga and Jabuti-toro, would have been known as “made men,” men who had murdered – “made their bones” – to prove their worth as members of the Family. In the equally elliptical language of the Chayacuro, they were kakaram, “powerful ones.” Their power derived from their success at assassination. Both had killed enemies. Both had taken heads.

They were dressed almost identically. Of anything that we would describe as clothing, they had only woven kilts of dyed cotton. But they did not think of themselves as naked. Heavy necklaces of jaguar teeth, boar tusks, nuts, and shells hung in layered profusion around their necks. Their faces were dyed orange-red with achiote, their chests painted in ancient designs with white clay. Sharpened quills of blue and green macaw feathers pierced their nasal septums, and thin bamboo tubes and more feathers ran through their earlobes. Their glossy, black hair had been carefully trimmed into neat bangs and tightly bound with headbands.

Beside them lay nine-foot-long hardwood blowguns, meticulously carved and hollowed out and lovingly polished. Around each man’s neck was slung a palm-frond quiver of darts from which dangled a small woven bag of cottonlike kapok. They were totally unafraid. The ayahuasca had made their bodies hard; they could not be harmed by others.

“I say again,” Jabuti-toro whispered forcefully. “We wait. We do not kill those who are not our enemies.”

Matsiguenga grunted his acceptance, but he had already made up his mind.