Three Inca mummies found near the lofty summit of Volcán Llullaillaco in Argentina were so well preserved that they put a human face on the ancient ritual of capacocha—which ended with their sacrifice.

Now the bodies of 13-year-old Llullaillaco Maiden and her younger companions Llullaillaco Boy and Lightning Girl have revealed that mind-altering substances played a part in their deaths and during the year-long series of ceremonial processes that prepared them for their final hours.

Under biochemical analysis, the Maiden's hair yielded a record of what she ate and drank during the last two years of her life. This evidence seems to support historical accounts of a few selected children taking part in a year of sacred ceremonies—marked in their hair by changes in food, coca, and alcohol consumption—that would ultimately lead to their sacrifice. (Related: "Lofty Ambitions of the Inca.")

In Inca religious ideology, the authors note, coca and alcohol could induce altered states associated with the sacred. But the substances likely played a more pragmatic role as well, disorienting and sedating the young victims on the high mountainside to make them more accepting of their own grim fates.

Well-Preserved History

The Maiden and her young counterparts, found in 1999, exist in a remarkable state of natural preservation due to frigid conditions just below the mountain's 22,110-foot (6,739-meter) summit.

"In terms of mummies that are known around the world, in my opinion she has to be the best preserved of any of the mummies that I'm aware of," said forensic and archaeological expert Andrew Wilson, of the University of Bradford (U.K.). "She looks almost as if she's just fallen asleep."

It is this incredible level of preservation that made possible the kinds of technical analysis that, paired with the pristine condition of the artifacts and textiles arrayed in the tomb-like structure, allowed experts to re-create the events that took place in this thin air some 500 years ago.

"I suppose that's what makes this all the more chilling," Wilson added. "This isn't a desiccated mummy or a set of bones. This is a person; this is a child. And this data that we've generated in our studies is really pointing to some poignant messages about her final months and years."

Before the Final Day

Because hair grows about a centimeter a month and remains unchanged thereafter, the Maiden's long, braided locks contain a time line of markers that record her diet, including consumption of substances like coca and alcohol in the form of chicha, a fermented brew made from maize.

The markers show she appears to have been selected for sacrifice a year before her actual death, Wilson explained. During this period her life changed dramatically, as did her surging consumption of both coca and alcohol, which were then controlled substances not available for everyday use. "We suspect the Maiden was one of the acllas, or chosen women, selected around the time of puberty to live away from her familiar society under the guidance of priestesses," he said, noting that this practice is described in the accounts of Spaniards who chronicled information on such rites given to them by the Inca.

A previous DNA and chemical study, also led by Wilson, examined changes in the Maiden's diet and found marked improvements during the year before her death, including the consumption of elite foods like maize and animal protein, perhaps llama meat. Now it's clear that the Maiden's consumption of coca also rose heavily throughout the year before her death, spiking dramatically 12 months before her death and again 6 months before her death. (Related: "Thousands of Inca Mummies Raised From Their Graves.")

"These data fit with the suggestion that she was perhaps leading an ordinary or even peasant lifestyle up to that point, but a year before her death she's selected, effectively removed from that existence and the lifestyle that was familiar to her, and projected into a different existence," Wilson said. "And now we see a massive change in terms of the use of coca."

The Maiden consistently used coca at a high level during the last year of her life, but her alcohol consumption surged tellingly only in her last weeks.

"We're probably talking about the last six to eight weeks, which show that very altered existence, that she's either compliant in taking this or is being made to ingest such a large quantity of alcohol. Certainly in her final weeks she's again entering a different state, probably one in which these chemicals, the coca and the chicha alcohol, might be used in almost a controlling way in the final buildup to the culmination of this capacocha rite and her sacrifice."

On the day of the Maiden's death the drugs may have made her more docile, putting her in a stupor or perhaps even rendering her unconscious. That theory seems to be supported by her relaxed, seated position inside the tomb-like structure, and the fact that the artifacts around her were undisturbed as was the feathered headdress she wore as she drifted off to death. Chewed coca leaves were found in the mummy's mouth upon her discovery in 1999.

The younger children show lower levels of coca and alcohol use, perhaps due to their lesser status in the ritual itself, or to their differences in age and size. "Perhaps as an older child there was a greater need to bring the Maiden to that point of sedation," Wilson said.

And while other capacocha sites show evidence of violence, like cranial trauma, these children were left to slip off peacefully. "Either they got it right, in terms of perfecting the mechanisms of performing this type of sacrifice, or these children went much more quietly," Wilson explained.

State-Sanctioned Sacrifices

Kelly Knudson, an archaeological chemist at Arizona State University, wasn't involved with the research but said the exciting study shows how archaeological science can help us understand both the intimate details of human lives and larger ancient societies.

"Seeing increases in both the consumption of alcohol and coca is very interesting, both in terms of the capacocha sacrifices and their lives before they died, and also in terms of what it can tell us about Inca coercion and control," Knudson said.

The system of control that brought these children to a remote mountaintop at extreme altitude shows all the hallmarks of state support at the highest level, the study's authors suggest, and may have occurred as part of a military and political expansion of the Cuzco-based empire that took place just prior to the arrival of the Spanish.

"The sort of logistical support needed even today to work at this altitude is extensive," Wilson explained. "And here we're talking about evidence that points to the highest possible, imperial-level support. There are artifacts and clothes that are elite and refined products coming from effectively the four corners of the Inca Empire."

Such artifacts include figures made of spondylus shells, brought from the coast, and feathered headdresses from the Amazon Basin. Well-crafted statues of gold and silver, adorned with finely woven miniature clothing, were also available only to the highest levels of society. "I think the whole assemblage represents their status and also the symbolism that this was undertaken under the highest possible sanction," he added. Wilson and his co-authors suggest that such sacrifices may have been a highly stratified means to help exert social control over large areas of conquered territories.

(Last year a study published in PloS ONE showed that the Maiden was suffering from a lung infection at the time of the sacrifice.)

Evidence Supports Early Spanish Chronicles

Johan Reinhard, a National Geographic Society Explorer-in-Residence, discovered the mummies in 1999 with colleague Constanza Ceruti, of the Catholic University of Salta (Argentina).

Reinhard, a co-author of the new study, said he's particularly interested in how the findings compare to what's been written in the historical chronicles of such ceremonies, penned by early Spanish explorers to the New World. "They describe how these ceremonies took place, but they weren't firsthand accounts; no Spanish ever saw one of these personally," Reinhard said. "They depended on what the Inca had told them about what happened."

(In the mid-16th century, for example, Juan de Betanzos wrote of widespread child sacrifices, up to a thousand individuals, on the testimony of his wife—who had previously been married to none other than the Inca Emperor Atahualpa.)

Now the data appear to match the kinds of events described in the chronicles, Reinhard said. "All of a sudden you have this picture where you can almost see what they are going through. Increased attention is paid to them in terms of better food and coca, which was used in ceremonies and wasn't in very common use. This kind of increased attention paid to these children is exactly what you read in the chronicles."

For example, Reinhard said, it's not surprising to see an increase in coca consumption during the year before the death of a chosen child like the Maiden because of the tales told in the chronicles.

"They talk about pilgrimages going to Cuzco and a series of ceremonies during which these children would be sent from one place to another on long pilgrimages. I think it's also interesting that there is a six-month period associated with these largest spikes in coca use," he added. "It could be six months related to something else, but a hypothesis to throw out there is that this corroborates historical accounts that some of these Virgins of the Sun were taken to solstice ceremonies during the year before they were taken off to their deaths."

Today the mummies reside in the Museo de Arqueología de Alta Montaña (MAAM) in Salta, Argentina. The extent to which their physical remains may support historical and archaeological records is exciting, Wilson added, but it is also chilling that the children remain so recognizably human even in death.

"For me it's almost like the children are able to reach out to us to tell us their own stories," he said. "Hair, especially, is such a personal thing, and here it's able to provide some compelling evidence and tell us a very personal story even after five centuries."