Factual error: During the big sacrifice scene an eclipse happens. An eclipse occurs when the moon passes between the earth and the sun. Later, apparently that night, the night mood is set by a shot of a full moon. The moon cannot be full until fourteen days after an eclipse, when it is directly opposite the sun.
Factual error: When Jaguar Paw runs into the huge pit of corpses, all is completely quiet and still. No people or animals are to be seen. This much unprotected meat in the topics would attract hundreds of vultures and other scavengers.
Answer: It is not specifically identified, but it appears to be the degenerative neurological disease called kuru. It is fatal and believed to have been spread in ancient sub-tropical cultures by cannibalism. Its symptoms resembles the encephalopathy disease known as Creutzfeldt-Jakob (Mad Cow), which is also called the laughing sickness, and is contracted by eating contaminated flesh.
raywest ★