She was killed at the age of 13 and placed in a mountaintop shrine in the Argentine high Andes--a sacrifice to the gods. There she lay for some 500 years until 1999, when archaeologists recovered her frozen body along with those of two other separately entombed children, a boy and a girl both between four and five years old. Researchers have long recognized that the three youngsters—the so-called Llullaillaco Maiden, Llullaillaco Boy and Lightning Girl--were victims of the Inca ritual of child sacrifice, or capacocha. A new study of their naturally mummified remains further illuminates the events leading up to their interment.

Chemical analyses of the hair of the children show that all three received coca leaves (from which cocaine is derived) and alcohol before they died. Twelve months before the 13-year-old maiden was killed, her consumption of coca surged. Meanwhile, her intake of alcohol—probably in the form of chicha, which is typically made from maize--peaked in her last weeks. And computed tomographic (CT) scanning revealed a large wad of coca leaves in her mouth that she had been chewing in her final moments. Andrew S. Wilson of the University of Bradford in the U.K. and his colleagues describe the findings in a report to be published online this week in the Proceedings of the National Academy of Sciences USA.

The exact nature of the event or events that led to the sacrifice of these children is unknown. It could have been an annual Incan occasion, or it might have been an unscheduled incident, such as the death of a ruler or a natural disaster. Whatever the case, the maiden received significantly more of these substances than the younger children did, possibly suggesting “a greater need to sedate her,” the researchers report. They observe that the posture of the girl's body and the undisturbed arrangement of her garments and surrounding ceremonial artifacts indicate that she was heavily sedated or dead when she was placed in the shrine.

“Coca and alcohol were substances that induced altered states interpreted as sacred, and which could suggest to victims and those associated with them the proximity of the divine beings whose continued benevolence was underwritten by these rites,” Wilson and his co-authors write. “From a cross-cultural perspective, the psychologically deadening, disorienting, and mood-modifying effects of these psychoactive compounds on young victims, for whom any kind of informed consent to their own deaths cannot be unproblematically presumed, should not be downplayed.”

As for the parents compelled to sacrifice their children, they would have done so with a smile if they knew what was good for them. The authors note that according to the 1653 writings of Spanish Jesuit missionary Bernabé Cobo, "'it was a major offense to show any sadness,' and that 'they were obliged to do it with gestures of happiness and satisfaction, as if they were taking their children to bestow upon them a very important reward.'"