When the 17-year-old crown prince of Spain, Don Carlos, fell down a set of stairs in 1562, he threw his whole country into a state of uncertainty about the future. Especially his father, King Philip II, who despite being the most powerful man in the world, was helpless in the face of his heir's terrible head wound.

As contributor Latif Nasser, a graduate student in the History of Science Department at Harvard, explains, none of the leading remedies of the day--bleeding, blistering, purging, or drilling--helped. King Philip II decided he needed a miracle to save his son. So he commissioned one from a highly-skilled clockmaker, and made a deal with God that led to an intricate mechanical creation.

Elizabeth King, a professor at Virginia Commonwealth University, describes how--according to legend--Philip II's plan played out.And Jad and Latif head to the Smithsonian to meet curator Carlene E. Stephens, who shows them the inner workings of a nearly 450-year-old monkbot.