Kato turned and led Ty, Nora, and Maria back through the passage the way they had come until he found a small alcove.

A rusted metal gate stood at the alcove’s entrance. Kato raked his flashlight over it, inspecting the hinges, then the latch. There was no lock there.

He grasped one of the bars and pushed, eliciting a sharp squeak like nails on a chalkboard.

Ty winced at the sound, which could very well get them killed down here. Still, he said nothing. He had to place his trust in Kato now.

Kato paused, letting the sound fade.

In the distance, the voices grew louder. The splashing stopped.

Slowly, Kato pushed the gate again, and this time the squeak was quieter. He stopped when the gap was barely wide enough to slip through, then crept forward.

In the beam of light carving through the darkness, Ty saw that the alcove was, in fact, a small passage that connected to another tunnel—a larger one that looked as though it may have been an underground railway. In the middle of the tunnel was a flat-top mound made of gravel with rounded indentions every few feet, like inverted speed bumps in the gravel road. Ty figured the railroad timbers had once lain where the holes were, but someone had removed them, probably a long time ago.

Kato moved to the end of the small passageway but didn’t shine his flashlight outward; he kept it pointed at his torso, preventing a large beam of light from issuing forth. In the soft glow, he peeked out into the tunnel, then clicked off his flashlight and crouched. He motioned for Ty to do the same.

In the darkness, they waited, listening. Ty saw what Kato’s plan was: if the people searching came the way they had come, they could enter this

other tunnel and escape.

The voices drew closer, their words more sporadic. Boots pounded the stone floor.

First one, then another, and then a third beam of light shone into the passage they had just retreated from. In the dim glow, Ty saw Kato reach out and take Maria’s hand and motion for her to reach out to Nora. The two women clasped hands, and Nora offered her palm to Ty. The touch of her warm skin was soothing, a contrast to the cold, dark place.

Kato crept forward, and soon Nora was pulling at Ty’s hand, and they emerged from the passage between the tunnels, following the abandoned tracks.

It was darker here—the light from the search party in the other tunnel was fading by the second. So were the sounds of their boots on the stone floor.

Kato led them, pulling them by the chain of hands like a tugboat leading the way through murky, treacherous waters.

The only sound was the crunch of their shoes on the loose gravel beside the mound. Ty felt as though the four of them were floating in the underworld, disembodied, only their souls drifting along, the touch of Nora’s hand his only connection to anything real, the last string that tethered him to reality.

Abruptly, she pulled him to the left. He stumbled on the gravel, kicking rocks, the sound grating after the near silence.

“You okay?” Nora whispered. “I’m fine.”

They moved slower in the blackness then, and Ty felt the air change. The dampness returned as they slipped out of the large tunnel and into another alcove.

How had Kato known where the entrance was? He must have seen the other connector tunnel before and timed their march, counting his steps and then feeling for the opening along the wall when they were close.

He led them down the small passage, and Ty heard the slight creaking of metal, possibly another gate, before they stopped again.

For a fraction of a second, Kato flicked his flashlight on, pointed inward at himself, stole a glance down the original passage they had been on, and clicked it off.

“It’s clear,” he whispered. “Keep your flashlight off, Ty.”

Nora’s hand pulled at Ty’s, and they were once again moving through the tunnel, which was quiet now. They turned several times, until the passage opened onto a newer section of tunnel that had diffuse light drifting down from above. Ty thought it looked like some sort of underground utility maintenance tunnel or a security passage. Periodically, there were locked grates above with metal ladders leading to round openings that Ty assumed were manholes.

With the aid of the dim light, they moved faster, jogging.

Up ahead, flashlights lanced out through a side tunnel—a search party moving to intersect with them.

Kato came to a halt, the others piling up behind him.

The Navy SEAL glanced behind them, and Ty followed his gaze, to the light emerging there. The sound of voices followed. The searchers had split into two groups—one behind, one ahead. They were closing in.

“Hurry,” Kato said, voice low, as he surged forward. “We’re close to the exit.”

Up ahead, the beams of light turned into the tunnel and raked across the four of them.

“Stop!” a voice yelled. Kato barreled ahead.

“We’ll shoot!” the man’s voice called.

Kato turned left, into an opening with stone steps leading up into darkness. Ty was about to ask what the plan was when Kato reached some sort of metal door, switched his light on, and stopped.

Was it locked? Ty heard him rattling something.

Behind them, the lights were growing brighter, the voices louder.

A gunshot rang out, deafening in the cramped space. Before Ty could ask what had happened, Kato threw open a metal door. Moonlight poured in, accompanied by the glow of streetlights. The only sound was the distant roar of a truck.

Kato climbed the stairs, rifle at the ready, the others close behind.

Ty scanned around them, surprised at what he saw. The Smithsonian Castle was directly ahead. The towering monolith of the Washington Monument lay to the right, lighted in all its glory. The United States Capitol loomed to the left, also lit up in the night.

They were on the National Mall. It was deserted at this hour—except for three groups of armed soldiers charging across the grass, converging on

them.

Ty’s first thought was that the shot had drawn the attention of Capitol Police. But these weren’t Capitol Police. They were wearing military fatigues. Ty couldn’t tell what branch. They carried rifles with laser sights, their beams trained on the group, red dots dancing across their bodies like glowing bugs swarming in the night.

From the tunnel below, the shouts grew louder, the flashlights brighter.

Kato raised his rifle and pointed it at the oncoming groups, swiveling between them as if trying to decide who to shoot first.

“Ty,” he shouted. “What do you want to do here?”

Ty’s mind went into overdrive. If they were captured, by either side, there was no doubt in his mind that their captor would enter a code into the quantum radio medallion. If that was going to happen, Ty wanted to type the code himself. He wanted to control their destiny as much as he could. And he was pretty sure he was right about what code to key in.

He just didn’t know what would happen when he did.

He shoved the flashlight into his pocket and drew out the round metal object.

“Ty!” Kato called as the armed soldiers continued advancing on them from all directions and below.

Ty mentally repeated what he believed to be the key to using the device:

The Birthright.

The March of Humanity. Worlds & Time.

The Theory of Everything. In each, was a single clue. Birth.

March.

Time.

Everything.

They were the shape of the answer. In his mind’s eye, Ty saw the file folders he’d been given for the genomic matches. The cover pages contained photos and birth dates of the three others:

March.

July.

August.

And his birth date: April.

On the quantum radio medallion, he pressed the third symbol. It lit yellow and vibrated as he pressed it. Then the fourth, then the seventh, and finally the eighth symbol.

His vision blurred.

The world around him disappeared.

And in the blink of an eye, it was back. But the world he saw wasn’t the same.