Was it a famous math problem in disguise?
An astronomical calculation?
A code within a code?
With only fifteen minutes until closing, she knew it was hopeless—and decided right then and there to spend the night in the museum.
It was the only way. She couldn’t risk losing a whole day. If a guard caught her, she could claim she’d had a fainting spell and talk her way out. It wasn’t like she was stealing anything.
But where to hide?
There were movies about this sort of thing, and possibilities flooded her mind. What about a storage room or a coat closet? A break room? If she had a screwdriver, she thought she could get into the air ducts.
To avoid getting locked in somewhere, she considered one of the exhibits. Could she hide under the blue whale? Inside a model dinosaur? The planetarium was a good choice. She certainly knew her way around, and it would be especially dark when the lights went out.
In the end, what really mattered were the guards and the cameras. She decided to stay as close as possible to the Hall of Mexico and Central America, so she wouldn’t have to traipse across the museum. Thankfully, she had seen no cameras aimed at the sun stone. Was that by design? Another machination of the Leap Year Society? Or just good luck?
Her mind was racing. She had to decide.
With a firm set to her jaw, she tossed her tea in the trash and walked calmly to the first-floor restroom located beside the stairwell leading to the Hall of Mexico and Central America. If someone caught her inside, she could pretend she was sick.
And if she solved the puzzle, all she had to do was climb the stairs, duck into the hall, and aim the Star Phone.
A loudspeaker announced the closing of the museum. Andie huddled in a stall with her feet on the toilet and tried to remain calm. She changed her mind, opened the door, and stood behind it, leaving the stall exposed. The door was tall for a bathroom and almost touched the floor. Her ruse depended on how carefully the guard checked the restroom, and she thought she had a better chance with an open door than a closed one.
Ten minutes later, when someone walked in, Andie held her breath, listening to the squeak of shoes. If the guard bent to check beneath the doors, Andie would easily be seen.
But the guard was careless. He or she made a quick sweep of the restroom, pushing open a few doors, and Andie heard footsteps pass right by her stall. She had made a good decision. All told, the guard spent about five seconds in the bathroom before killing the lights on the way out.
Andie exhaled a slow, silent breath.
With any luck, she would have a few hours before the cleaning crew arrived.
Half an hour later, with no progress on the puzzle, Andie wondered if the secret lay somewhere inside the Hall of Mexico and Central America. It was mostly a collection of figurines, pottery, and jewelry. Gold and jade featured prominently. She had canvassed it closely and pointed the Star Phone at almost every item, but maybe she had missed something.
Before she risked exposing herself to the cameras, she decided to explore other solutions from the safety of the bathroom. She sat with her back against the stall door in the darkness and researched on Zawadi’s phone. The solar battery was incredibly long-lasting and still had half its power.
At first she Googled more math puzzles, since the structure of the four equations looked suspiciously akin to brainteasers she had seen in the past. She did find a similar motif, but none of the answers gave her any insight into her own puzzle. What was the trick?
She remembered Cal’s admonition in Sicily that the puzzles were designed to shine a light on historical achievements, not esoteric equations.
Why had Dr. Corwin chosen to highlight the Aztecs, anyway? she asked herself.
Most scholars focused on the Mayans as paragons of Mesoamerican genius. During a civilization that had lasted over three thousand years—a fact that boggled Andie’s mind—the accomplishments of the Mayans were well-documented: A sophisticated logosyllabic writing system, which was one of a handful throughout history to develop independently from other civilizations. Advanced crop cultivation techniques that included subterranean repositories to store water for the dry season. The invention of chocolate, an intricate legal system, and elastics made of latex long before Charles Goodyear patented vulcanized rubber. Andie revered the ancient Mayan astronomers, whose temple-top observatories rising above the Yucatán had recorded meticulous data.
Mayan genius: check.
So what about the Aztecs?
She started Googling their accomplishments. The last great Mesoamerican empire, the Aztecs had risen to power in the fourteenth century AD, long after the Mayans had begun to decline. Central Mexico was far more conducive to warfare than the Yucatán jungle, and the Aztec Empire was steeped in blood from the beginning. Every single male was conscripted. Elite special forces carried razor-sharp obsidian swords and wore padded armor beneath elaborate animal-skin costumes. Controlling millions of people at the height of the empire, Aztec warriors struck fear into neighboring states, and might have advanced much further had they not encountered the superior technology and exotic diseases of the Spanish.
Despite their military prowess, the Aztecs were also sophisticated traders, who established an imperial bureaucracy to govern their empire. They documented their achievements with extensive codices and erected astonishing temples and buildings. Andie was surprised to learn the Great Pyramid of Tepanapa, buried under a hill near modern-day Mexico City, was the largest man-made pyramid in history—surpassing even those in Egypt.
Like their Mayan predecessors, from whom they borrowed heavily, the Aztecs were incredible astronomers, mathematicians, artists, philosophers, and agriculturists. They coaxed floating gardens out of swampland and established compulsory education for their children. Aztec physicians developed extensive herbology codices that included the use of analgesics.
Great. I get it. They were as advanced as we are, in their