“We make—perfect team.”

Mr. Brewster came from the cabin and clapped a hand on each boy’s shoulder.

“You do make a perfect team,” he complimented. “Just remember it.”

They remembered it, several nights later, when they sat around the campfire after a cajaro dinner.

“Tomorrow,” stated Mr. Brewster, “we come to the Maipures Rapids.”

“Can we take the boat down through them?” queried Biff. “I mean, Kamuka and I?”

“None of our boats will shoot the Maipures,” said Mr. Brewster. “They are impassable. So are the rapids of the Atures, forty miles below. A road has been built around both rapids, so that trucks can transport us with our boats.”

Joe Nara gave a high-pitched snort.

“That’s where Serbot will be waiting for us,” he declared. “That’s for sure.”

“I’m not so sure,” put in Hal Whitman. “After he sold us out to those Indians on the Casquiare, he probably headed back the other way, down the Rio Negro.”