“What is this place, Alexei?”

He says something in Russian, low and under his breath. Then he mutters, “I have no idea.”

Carefully, we go on. When the beam flashes across a giant urn I inch forward. It’s stone, but the interior is black. I rub my finger along the inside and realize it’s coated with soot.

Alexei looks at me. “This is where they used to light their fires,” he explains.

I walk forward, down a wide staircase onto the sunken floor. My light catches other urns. Some stone pedestals that look like places where ancient pillars might have crumbled. I point my light up and see mosaics covering the ceiling above us, catching the light, and I just know in my gut that it is inlaid with gold.

Alexei cranes his head upward, following the light. “Have you ever seen anything like it?”

I have, but I can’t say so.

Alexei looks at me. I can feel his gaze through the darkness. Our hands brush.

“Grace!” Alexei points in the dim light, so I flash the beam across the dusty floor, past cracks in the stone and plants that grow, even in the darkness. “Grace, are those …” I follow Alexei’s gaze, and then my light catches them.

“Footprints. Spence?” I ask.

“Who else?” Alexei shrugs.

Neither of us asks how a West Point cadet could have died here and ended up in the sea. Neither of us worries that in the dark there might be nothing we can find. We just ease forward, following in the footsteps of a dead man.

There are vines overhead. A bird squawks and I jump, suddenly grateful Alexei’s beside me.

“Don’t leave me in here, okay?” he asks, grinning and taking my hand. “This place is freaking me out.” In Alexei’s Russian accent, that sounds almost funny, and I can’t help but smile.

“Don’t worry, tough guy. I’ll protect you.”

We cross the massive room, following the footsteps until, as if by magic, they disappear. There’s a wall ahead. A dead end. I turn quickly, sweeping the beam of my light across the floor, but I can’t see where the feet might have retreated. Maybe they did, walking on the section of floor that isn’t as dusty. Or maybe …

I step away from the wall and look at it from a new angle.

“Okay,” Alexei says. “I suppose this is a dead end. I’m sorry, Gracie.”

I can feel him turning, backing away, but I can’t stop looking at the wall. I can’t stop thinking Spence was here. I know it. I can feel it. He was too intrigued when I saw him outside, and, according to Jamie, he wore his grandmother’s necklace every day of his life. He wasn’t the type to turn back just because something looked to be off-limits.

He came here.

And then he ended up dead.

“Gracie,” Alexei says. I can feel his hand on my arm. “We should go find the others. Perhaps they have had better luck.”

“No.” I shake my head. “Not yet.”

I start in the upper-left-hand corner of the wall and slowly sweep my light across it, moving in a gridlike pattern. I cover every inch. Every brick. Every loose piece of mortar and —

The mortar is loose, here in the right-hand corner. I step forward, reach out to touch the stones the way I’ve seen Ms. Chancellor do, pressing and pulling.

“Gracie, please. It doesn’t look stable. We should go.”

I know Alexei is looking at me like I’m a crazy person. I can hear it in the way he says my name. But it’s too late for looking crazy to bother me.

“Just a second. I think maybe …” The stones are turning, they’re easing into position, and a moment later, the floor shakes a little. The wall moves, sliding aside, revealing an empty space of echoing darkness, but as soon as I shine my light upon the floor I see more footprints.

Alexei is mumbling something that I think must be the Russian equivalent of Oh my freaking goodness.

But I don’t stop to think or reason, I just follow the footsteps to the other side of the wall, where there is nothing but blackness. The air feels different here — fresher. Even though the walls on either side of me are closer and the room feels smaller, when I shine my light forward it stretches out farther and farther and I know we’re not even close to the end.

“Gracie, we shouldn’t be here,” Alexei says, but even his voice is filled with wonder.

I turn my light upward and see that even here the ceiling is covered with images, faded but clear. In the first, a king is surrounded by six knights, each of them bowing before him, offering their swords.

“Look at that one,” Alexei says.

I cast my light over an image that looks vaguely familiar. It’s the room we just left, I realize, but it’s filled with piles of gold. Rubies, emeralds, and pearls overflow from chests, spilling out onto the floor.

Treasure.

Even though we’re standing still, my heart has started to pound too hard. The light shakes as my hand trembles.

“They almost look real,” Alexei says as the gems in the pictures catch the light, gold shining, diamonds glowing. A cold dread grips me.

“I think they are real,” I say, and just that quickly … I know.

We aren’t supposed to be here.

Spence wasn’t supposed to be here.

The last person who came to this place looking for treasure died, and it doesn’t matter that he ended up miles away from here — I know it isn’t safe.

“Gracie, I think we’d better get out of —”