Right! Aymaran was a fictional character.
As far as we know, the emperor did not select a young man to give a secret message to on the day of his execution in 1533. In the book, the emperor selected Aymaran because he was a chaski, an Inca running messenger, and could travel long distances carrying information and goods.
Although Aymaran was not a real person, the chaski network of runners was real. By relaying messages from one chaski to the next, information could be delivered from Cusco to Quito in one week. That's over 1,000 miles (or over 1,600 km)! How's that for a game of telephone?
The empire had a special road network for the messengers. There were rope bridges across rivers, long stone roads, and steep staircases built for the chaski. Transfer and rest stop buildings with water and supplies were called tambos. And as in the image at right, each runner carried a pututu (a horn made from a shell), and a quipu (rope accounting system).