I first read this book when I was in elementary school and was fascinated by the depiction of the Inca civilization. It made such an impression on me that years later I created a mathematics problem based on the quipu, knotted strings that was used by the Incas to create, store and transmit messages. Roca is a message runner; his role is to physically transport quipu from one point in the Inca Empire to another. This particular night the task is even more critical, a foreign army is on the march against the empire and the message he carries is a warning. Ordinarily, he would only run a short leg of the journey and transfer the message to the next runner in the sequence. However, enemy spies are trying to intercept the message and a puma attacks Roca. The next runner is attacked by the spies and injured, so he is unable to run his section of the route, which is the one that would take the message to the Emperor. Realizing the significance of his mission, Roca persists and is able to deliver the quipu to the Emperor's court and a catastrophe is averted. This short story is a combination of a tale of heroism as well as a history lesson. A short section on using quipu to store messages in the Inca language would be an excellent contribution to multicultural studies.