"All right, Dan," he said, "I'll go you. I've still got some of the money I saved up from my work this summer and I was going to spend part of it on tutoring this winter, anyway. I'll tutor under you, whenever I'm off duty, and if you can teach me to like figures, you're a good one. Any way, your cottage is so near that I can get right on the job if the station calls."
True to his word, a few days later Eric appeared at the tiny little cottage—it was scarcely more than a hut—which was the home of the eccentric old puzzle-maker. The top part of it was a home-made observatory, and the whole building looked a good deal like a large beehive.
"String in the corner," said the old man, after welcoming him. "Get him."
"It's all knotted, Dan," the boy replied, holding up a piece of rope with a couple of dozen strings hanging from it, of various colors, all intertwined.
"Of course he is," the old man replied. "Read him."
"What?" asked the boy.
"Read him," repeated the old man.
"What does it mean?"
"He's what Incas used to count treasure with," the old man said. "He's quipu, a copy of one Cortez found in City of Sun. You like to read what he says?"
"You bet I would."