Inside the domed room, the living men’s voices began to rise steadily, bouncing off the ceiling with strange acoustics.

Flossie leaned in close to Violet. “What’s going on?” It sounded as if they were arguing about something.

Violet listened in as the voices became even more heated, then she began to whisper as fast as she could, combining the arguing voices into one.

You’re the one who put him in the stupid skull with your strange death ritual. Now get him out!

I can’t get him out, you ridiculous man. He’s dead. It’s only his soul that’s in there.

But all we’ve been able to retrieve so far is some basic information on troop movements. It’s not enough. We need more.

Violet and Flossie’s eyes met. So it was true. He was getting information through to the living. Flossie’s lifeless heart sank as the voices rose again and Violet continued to translate.

What’s the point of Brun following Churchill around if he can’t tell us everything he’s seen and heard easily?

Don’t you understand that it’s not that simple? There is so much noise in the skull. So much disagreement. So much distraction.

Flossie reached out and clutched Violet’s arm. “The other person,” she said. “The other voice I heard. The second soul.”

Violet nodded in agreement, her eyes still on the men. Her hand reached out to grab at Flossie’s arm. “Oh, no!” she hissed.

Flossie took in as much of the scene as she could. The living officers had quieted down and stepped away, leaving the spiritualist alone with the crystal skull on its plinth. Viktor Brun stood above the skull, both hands on top of it. The spiritualist knelt on the floor, his hands on the skull as well. When all was silent, the spiritualist began to breathe slowly, in and out.

Meanwhile, one of the living officers hovered by the spiritualist’s side, notebook and pencil in hand.

For a long time, all was silent. And then the spiritualist began to murmur. At first his voice was halting and unsure, but as time passed, he began to sound surer of himself, the phrases rolling faster off his tongue.

“I can’t hear what he’s saying,” Flossie whispered into Violet’s ear, worried about being heard by Viktor Brun now that the room was so much quieter.

Violet closed her eyes, listening hard. “Something about the War Rooms and some names. Names of ships, I think.”

Flossie covered her mouth, stifling a gasp. “No! Violet, we have to do something.” She grabbed at both of Violet’s arms. “How can we stop him?”

Violet’s brow was furrowed with thought. “I don’t know, I . . . I think the only way would be to sever the connection. And the only way I can see to do that would be to destroy the crystal skull in the living world.”

“How? We can’t destroy something in the living world. And, oh —” Flossie remembered something. “The other person!”

Violet’s face fell. “You’re right. If we destroy the skull, not only would Viktor Brun’s soul be lost forever but the soul of the other person, too.”

Flossie knew how wrong it would be to destroy the soul of an innocent person. Without a soul, no person could ever be properly, and happily, at rest.

“I can’t think of any other way to stop him,” Violet said.

Flossie scrutinized the skull. It almost seemed to be alight as the flame fluttered and danced in front of it. As she watched, the spiritualist’s voice began to murmur again, and the officer beside him took more notes.

More information.

They didn’t have any time to waste. “Let’s go,” Flossie told Violet. “We’ve learned what we came here to find out. Now let’s see what we can do about it.”

It was as Flossie had said. They now knew what the Ahnenerbe’s mission was. They knew who was involved in it, what they were doing, and what they were capable of. They also knew that Viktor Brun could do what they had feared — he could pass messages to the living via the crystal skull.

The dead were now officially at war along with the living.

Safely back outside the castle, Violet and Flossie stopped at the end of the bridge. Flossie turned back toward the castle and caught a flash of black out of the corner of her eye. Wait, had that been . . . ? For a second she thought it might have been Hugo Howsham’s coat disappearing around the castle’s stone wall. She was seeing things. She needed to stop being so jumpy and concentrate. Just as she was about to speak, she noticed something in Violet’s expression.

“What is it?” Flossie asked.

“I’ve only now put two and two together,” Violet answered, moving the papers she held from one hand to the other. “Do you remember I told you about the Externsteine?”

“The rock formation?”

“Yes,” Violet said. “I heard them mention it just before we left, and they also said something about the upcoming full moon. It finally makes sense to me. I think they’re going to try to concentrate the connection between the two skulls and the worlds of the living and the dead by using the site during a full moon.”

“Would that work?” Flossie asked.

“Unfortunately, I think it would.”

Flossie wanted to slump onto the hard stone beneath her feet. She felt just the same as she had on first awakening in Highgate Cemetery when she had been told she was in charge of hundreds of thousands of interred. She couldn’t do this. She didn’t know how. Or what to do. Or when to do it.

“How will we know when the time is right?” Flossie asked.

“They’ll wait until the moon is at its highest peak. The spiritualist will be able to tell them exactly when that is, and I’ll be able to tell you. I’ve always been able to feel the waxing and waning of the moon, and I can feel it still, even in our world. Flossie, I think this could work well for us. If I’m right about what I think they have in mind, the crystal skull will be up high on the rock formation. It would be situated in quite a vulnerable spot.”

“What do you mean?”

“Well, one good push . . .”

Their eyes met as they thought about that second person. Flossie didn’t like it. She didn’t like it at all. But if they didn’t destroy the skull, how many other lives would be lost? There were no right answers to be had here. It seemed there never were in war.

“So, one push,” Flossie said. “But how? How can we move an object in the living world?”

It was clear that neither of them had any idea.

“We’ll think of a way,” Violet said.

“We have to,” Flossie replied, her gaze moving back to the hills beyond the castle. Once again, she wondered if she should tell Violet about Viktor Brun and her father. She wanted to, but still thought it would be unwise. If Hugo Howsham found out that she had a personal connection to Viktor Brun, she’d never hear the end of it.

Violet’s hand came to rest upon her arm. “Let’s return home,” she said.

Flossie opened her eyes directly outside Kensal Green Cemetery. She tapped her iron ring upon the small iron gates set inside the larger ones for the living. She expected Hugo Howsham to appear on the other side of the gates in an instant, and when he didn’t, she became wary. Had she seen him at Wewelsburg Castle? Then she caught sight of him on a path some distance away and he shot toward them, his top coat flying out impressively behind him. Somehow, that man always seemed one step ahead.

“Miss Birdwhistle.” Hugo Howsham swung his key on its iron ring into his hand and unlocked the gate to his cemetery. As he pulled the gate open for his sister, Flossie took a step back, which she instantly regretted — she hated letting him think for one second that she wasn’t up to her role, even if she often felt that way herself.

“I’m afraid we don’t have very good news,” Flossie said, gesturing toward the papers Violet held.

“I’ll explain everything to Hugo. And I’ll fetch you when the full moon is near,” Violet said hurriedly. Flossie understood — it was best to leave her to break the news to her brother. She would know how to handle him. “Don’t worry,” Violet added. “We’ll work something out.”

Hugo Howsham watched the pair closely, but when he saw that no more information was immediately forthcoming, he returned to locking the gates.

“Before you go, I have a message for you,” he said when he was done with the lock and Violet was standing safely beside him. “The Turnkey of Tower Hamlets was here. She said to tell you that you must go to see someone called Grace immediately. Apparently she and her sister have both been taken into surgery.”