“How—how did you… ?” He gulped. “Who are you?”

“A child of Athena,” Annabeth said again. “But not just any child. I am…uh, the mater in my sisterhood. The magna mater, in fact. There are no mysteries to me. Mithras cannot hide anything from my sight.”

“The magna mater!” a ghost wailed in despair. “The big mother!”

“Kill her!” One of the ghosts charged, his hands out to strangle her, but he passed right through her.

“You’re dead,” Annabeth reminded him. “Sit down.”

The ghost looked embarrassed and took his seat.

“We do not need to kill you ourselves,” the pater growled. “Mithras shall do that for us!”

The statue on the altar began to glow.

Annabeth pressed her hands against the bricked-in doorway at her back. That had to be the exit. The mortar was crumbling, but it was not weak enough for her to break through with brute force.

She looked desperately around the room—the cracked ceiling, the floor mosaic, the wall paintings, and the carved altar. She began to talk, pulling deductions from the top of her head.

“It is no good,” she said. “I know all. You test your initiates with fire because the torch is the symbol of Mithras. His other symbol is the dagger, which is why you can also be tested with the blade. You want to kill me, just as…uh, as Mithras killed the sacred bull.”

It was a total guess, but the altar showed Mithras killing a bull, so Annabeth figured it must be important. The ghosts wailed and covered their ears. Some slapped their faces as if to wake up from a bad dream.

“The big mother knows!” one said. “It is impossible!”

Unless you look around the room, Annabeth thought, her confidence growing.

She glared at the ghost who had just spoken. He had a raven badge on his toga—the same symbol as on the floor at her feet.

“You are just a raven,” she scolded. “That is the lowest rank. Be silent and let me speak to your pater.”

The ghost cringed. “Mercy! Mercy!”

At the front of the room, the pater trembled—either from rage or fear, Annabeth wasn’t sure which. His pope hat tilted sideways on his head like a gas gauge dropping toward empty. “Truly, you know much, big mother. Your wisdom is great, but that is all the more reason why you cannot leave. The weaver warned us you would come.”

“The weaver…” Annabeth realized with a sinking feeling what the pater was talking about: the thing in the dark from Percy’s dream, the guardian of the shrine. This was one time she wished she didn’t know the answer, but she tried to maintain her calm. “The weaver fears me. She doesn’t want me to follow the Mark of Athena. But you will let me pass.”

“You must choose an ordeal!” the pater insisted. “Fire or dagger! Survive one, and then, perhaps!”

Annabeth looked down at the bones of her siblings. The failures of your predecessors will guide you.

They’d all chosen one or the other: fire or dagger. Maybe they’d thought they could beat the ordeal. But they had all died. Annabeth needed a third choice.

She stared at the altar statue, which was glowing brighter by the second. She could feel its heat across the room. Her instinct was to focus on the dagger or the torch, but instead she concentrated on the statue’s base. She wondered why its legs were stuck in stone. Then it occurred to her: maybe the little statue of Mithras wasn’t stuck in the rock. Maybe he was emerging from the rock.

“Neither torch nor dagger,” Annabeth said firmly. “There is a third test, which I will pass.”

“A third test?” the pater demanded.

“Mithras was born from rock,” Annabeth said, hoping she was right. “He emerged fully grown from the stone, holding his dagger and torch.”

The screaming and wailing told her she had guessed correctly.

“The big mother knows all!” a ghost cried. “That is our most closely guarded secret!”

Then maybe you shouldn’t put a statue of it on your altar, Annabeth thought. But she was thankful for stupid male ghosts. If they’d let women warriors into their cult, they might have learned some common sense.

Annabeth gestured dramatically to the wall she’d come from. “I was born from stone, just as Mithras was! Therefore, I have already passed your ordeal!”

“Bah!” the pater spat. “You came from a hole in the wall! That’s not the same thing.”

Okay. So apparently the pater wasn’t a complete moron, but Annabeth remained confident. She glanced at the ceiling, and another idea came to her—all the details clicking together.

“I have control over the very stones.” She raised her arms. “I will prove my power is greater than Mithras. With a single strike, I will bring down this chamber.”

The ghosts wailed and trembled and looked at the ceiling, but Annabeth knew they didn’t see what she saw. These ghosts were warriors, not engineers. The children of Athena had many skills, and not just in combat. Annabeth had studied architecture for years. She knew this ancient chamber was on the verge of collapse. She recognized what the stress fractures in the ceiling meant, all emanating from a single point—the top of the stone arch just above her. The capstone was about to crumble, and when that happened, assuming she could time it correctly…

“Impossible!” the pater shouted. “The weaver has paid us much tribute to destroy any children of Athena who would dare enter our shrine. We have never let her down. We cannot let you pass.”

“Then you fear my power!” Annabeth said. “You admit that I could destroy your sacred chamber!”

The pater scowled. He straightened his hat uneasily. Annabeth knew she’d put him in an impossible position. He couldn’t back down without looking cowardly.

“Do your worst, child of Athena,” he decided. “No one can bring down the cavern of Mithras, especially with one strike. Especially not a girl!”

Annabeth hefted her dagger. The ceiling was low. She could reach the capstone easily, but she’d have to make her one strike count.

The doorway behind her was blocked, but in theory, if the room started to collapse, those bricks should weaken and crumble. She should be able to bust her way through before the entire ceiling came down—assuming, of course, that there was something behind the brick wall, not just solid earth; and assuming that Annabeth was quick enough and strong enough and lucky enough. Otherwise, she was about to be a demigod pancake.

“Well, boys,” she said. “Looks like you chose the wrong war god.”

She struck the capstone. The Celestial bronze blade shattered it like a sugar cube. For a moment, nothing happened.

“Ha!” the pater gloated. “You see? Athena has no power here!”

The room shook. A fissure ran across the length of the ceiling and the far end of the cavern collapsed, burying the altar and the pater. More cracks widened. Bricks fell from the arches. Ghosts screamed and ran, but they couldn’t seem to pass through the walls. Apparently they were bound to this chamber even in death.

Annabeth turned. She slammed against the blocked entrance with all her might, and the bricks gave way. As the cavern of Mithras imploded behind her, she lunged into darkness and found herself falling.

Chapter 35

Annabeth thought she knew pain. She had fallen off the lava wall at Camp Half-Blood. She’d been stabbed in the arm with a poison blade on the Williamsburg Bridge. She had even held the weight of the sky on her shoulders.

But that was nothing compared to landing hard on her ankle.

She immediately knew she’d broken it. Pain like a hot steel wire jabbed its way up her leg and into her hip. The world narrowed to just her, her ankle, and the agony.

She almost blacked out. Her head spun. Her breath became short and rapid.

No, she told herself. You can’t go into shock.

She tried to breathe more slowly. She lay as still as possible until the pain subsided from absolute torture to just horrible throbbing.

Part of her wanted to howl at the world for being so unfair. All this way, just to be stopped by something as common as a broken ankle?

She forced her emotions back down. At camp, she’d been trained to survive in all sorts of bad situations, including injuries like this.

She looked around her. Her dagger had skittered a few feet away. In its dim light she could make out the features of the room. She was lying on a cold floor of sandstone blocks. The ceiling was two stories tall. The doorway through which she’d fallen was ten feet off the ground, now completely blocked with debris that had cascaded into the room, making a rockslide. Scattered around her were old pieces of lumber—some cracked and desiccated, others broken into kindling.

Stupid, she scolded herself. She’d lunged through that doorway, assuming there would be a level corridor or another room. It had never occurred to her that she’d be tumbling into space. The lumber had probably once been a staircase, long ago collapsed.

She inspected her ankle. Her foot didn’t appear too strangely bent. She could feel her toes. She didn’t see any blood. That was all good.

She reached out for a piece of lumber. Even that small bit of movement made her yelp.

The board crumbled in her hand. The wood might be centuries old, or even millennia. She had no way of knowing if this room was older than the shrine of Mithras, or if—like the labyrinth—the rooms were a hodgepodge from many eras thrown randomly together.

“Okay,” she said aloud, just to hear her voice. “Think, Annabeth. Prioritize.”

She remembered a silly wilderness survival course Grover had taught her back at camp. At least it had seemed silly at the time. First step: Scan your surroundings for immediate threats.

This room didn’t seem to be in danger of collapsing. The rockslide had stopped. The walls were solid blocks of stone with no major cracks that she could see. The ceiling was not sagging. Good.

The only exit was on the far wall—an arched doorway that led into darkness. Between her and the doorway, a small brickwork trench cut across the floor, letting water flow through the room from left to right. Maybe plumbing from the Roman days? If the water was drinkable, that was good too.

Piled in one corner were some broken ceramic vases, spilling out shriveled brown clumps that might once have been fruit. Yuck. In another corner were some wooden crates that looked more intact, and some wicker boxes bound with leather straps.

“So, no immediate danger,” she said to herself. “Unless something comes barreling out of that dark tunnel.”

She glared at the doorway, almost daring her luck to get worse. Nothing happened.

“Okay,” she said. “Next step: Take inventory.”

What could she use? She had her water bottle, and more water in that trench if she could reach it. She had her knife. Her backpack was full of colorful string (whee), her laptop, the bronze map, some matches, and some ambrosia for emergencies.

Ah…yeah. This qualified as an emergency. She dug the godly food out of her pack and wolfed it down. As usual, it tasted like comforting memories. This time it was buttered popcorn—movie night with her dad at his place in San Francisco, no stepmom, no stepbrothers, just Annabeth and her father curled up on the sofa watching sappy old romantic comedies.