“There’s no need for experiments. I already know why weavers can have children with blood-rage vampires.” The answer was running up my arms in letters and symbols from languages long dead or never spoken except by witches performing spells. The cords in my body were twisting and turning into brightly hued helices of yellow and white, red and black, green and silver.

“So the answer was in the Book of Life,” Sarah said, “just as the vampires thought it would be.”

“And it all began with a discovery of witches.” I pressed my lips together to avoid revealing any more. “Marcus is right. If we go after Benjamin without a plan and the support of other creatures, he will win. And Matthew will die.”

“I’m sending you a road map of southern and eastern Poland now,” Nathaniel said over the speaker.

Another window opened on the screen. “Here is Auschwitz.” A purple flag appeared. “And here is Majdanek.” A red flag marked a location on the outskirts of a city so far to the east it was practically in Ukraine. There were miles and miles of Polish ground in between.

“Where do we start?” I asked. “At Auschwitz and move east?”

“No. Benjamin will not be far from Lublin,” Ysabeau insisted. “The witches we interrogated when Philippe was found said the creature who tortured him had long-standing ties to that region. We assumed they were talking about a local Nazi recruit.”

“What else did the witches say?” I asked.

“Only that Philippe’s captor had tortured the witches of Chelm before turning his attentions to my husband,” Ysabeau said. “They called him ‘the Devil.’”

Chelm. Within seconds I found the city. Chelm was just to the east of Lublin. My witch’s sixth sense told me that Benjamin would be there—or very close.

“That’s where we should start looking,” I said, touching the city on the map as though somehow Matthew could feel my fingers. On the video feed, I saw that he had been left alone with a dead child.

His lips were still moving, still singing . . . to a girl who would never hear anything again.

“Why are you so sure?” Hamish asked.

“Because a witch I met in sixteenth-century Prague was born there. The witch was a weaver—like me.” As I spoke, names and family lineages emerged on my hands and arms, the marks as black as any tattoo. They appeared for only a moment before fading into invisibility, but I knew what they signaled: Abraham ben Elijah was probably not the first—nor the last—weaver in the city. Chelm was where Benjamin had started his mad attempts to breed a child.

On the screen, Matthew looked down at his right hand. It was spasming, the index finger tapping irregularly on the arm of the chair.

“It looks as though the nerves in his hand have been damaged,” Marcus said, watching his father’s fingers twitch.

“That’s not involuntary movement.” Gallowglass bent until his chin practically rested on the keyboard. “That’s Morse code.”

“What is he saying?” I was frantic at the thought that we might already have missed part of the message.

“D. Four. D. Five. C. Four.” Gallowglass spelled out each letter in turn. “Christ. Matthew’s making no sense at all. D. X—”

“C4,” Hamish said, his voice rising. “DXC4.” He whooped in excitement. “Matthew didn’t walk into a trap. He sprang it deliberately.”

“I don’t understand,” I said.

“D4 and D5 are the first two moves of the Queen’s Gambit—it’s one of the classic openings in chess.” Hamish went to the fire, where a heavy chess set waited on a table. He moved two pawns, one white and then one black. “White’s next move forces Black to either put his key pieces in jeopardy and gain greater freedom or play it safe and limit his maneuverability.” Hamish moved another white pawn next to the first.

“But when Matthew is White, he never initiates the Queen’s Gambit, and when he’s Black, he declines it. Matthew always plays it safe and protects his queen,” Baldwin said, crossing his arms over his chest. “He defends her at all costs.”

“I know. That’s why he loses. But not this time.” Hamish picked up the black pawn and knocked over the white pawn that was diagonal to it in the center of the board. “DXC4. Queen’s Gambit accepted.”

“I thought Diana was the white queen,” Sarah said, studying board. “But you’re making it sound like Matthew is playing Black.”

“He is,” Hamish said. “I think he’s telling us the child was Benjamin’s white pawn—the player he sacrificed, believing that it would give him an advantage over Matthew. Over us.”

“Does it?” I asked.

“That depends on what we do next,” Hamish said. “In chess, Black would either continue to attack pawns to gain an advantage in the endgame or get more aggressive and move in his knights.”

“Which would Matthew do?” Marcus asked.

“I don’t know,” Hamish said. “Like Baldwin said, Matthew never accepts the Queen’s Gambit.”

“It doesn’t matter. He wasn’t trying to dictate our next move. He was telling us not to protect his queen.” Baldwin swung his head around and addressed me directly. “Are you ready for what comes next?”

“Yes.”

“You hesitated once before,” Baldwin said. “Marcus told me what happened the last time you faced Benjamin in the library. This time, Matthew’s life depends on you.”

“It won’t happen again.” I met his gaze, and Baldwin nodded.

“Will you be able to track Matthew, Ysabeau?” Baldwin asked.

“Better than Verin,” she replied.

“Then we will leave at once,” Baldwin said. “Call your knights to arms, Marcus. Tell them to meet me in Warsaw.”

“Kuźma is there,” Marcus said. “He will marshal the knights until I arrive.”

“You cannot go, Marcus,” Gallowglass said. “You must stay here, with the babes.”

“No!” Marcus said. “He’s my father. I can scent him just as easily as Ysabeau. We’ll need every advantage.”

“You aren’t going, Marcus. Neither is Diana.” Baldwin braced his arms on the table and fixed his eyes on Marcus and me. “Everything until now has been a skirmish—a preamble to this moment.

Benjamin has had almost a thousand years to plan his revenge. We have hours. We all must be where we are most needed—not where our hearts lead us.“

“My husband needs me,” I said tightly.

“Your husband needs to be found. Others can do that, just as others can fight,” Baldwin replied.

“Marcus must stay here, because Sept-Tours has the legal status of sanctuary only if the grand master is within its walls.”

“And we saw how much good that did us against Gerbert and Knox,” Sarah said bitterly.

“One person died.” Baldwin’s voice was as cold and clear as an icicle. “It was regrettable, and a tragic loss, but if Marcus had not been here, Gerbert and Domenico would have overrun the place with their children and you would all be dead.”

“You don’t know that,” Marcus said.

“I do. Domenico boasted of their plans. You will stay here, Marcus, and protect Sarah and the children so that Diana can do her job.”

“My job?” My brows lifted.

“You, sister, are going to Venice.”

A heavy iron key flew through the air. I put my hand up, and it landed in my palm. The key was heavy and ornate, with an exquisite bow wrought in the shape of the de Clermont orobouros, a long stem, and a chunky bit with complicated star-shaped wards.

“What’s in Venice?” I owned a house there, I dimly recalled. Perhaps this was the key to it?

No one answered. Every vampire in the room was staring at my hand in shock. I turned it this way and that, but there didn’t seem to be anything odd about it other than the normal rainbow colors, marked wrist, and odd bits of lettering. It was Gallowglass who regained his tongue first.

“You cannot send Auntie in there,” he said, giving Baldwin a combative shove. “What are you thinking, man?”

“That she is a de Clermont—and that I am more useful tracking Matthew with Ysabeau and Verin than I am sitting in a council chamber arguing about the terms of the covenant.” Baldwin turned glittering eyes on me. He shrugged. “Maybe Diana can change their mind.”

“Wait.” Now it was my turn to look amazed. “You can’t—”

“Want you to sit in the de Clermont seat at the Congregation’s table?” Baldwin’s lip curved. “Oh, but I do, sister.”

“I’m not a vampire!”

“Nothing says you have to be. The only way that Father would agree to the covenant was if there were always a de Clermont among the Congregation members. The council cannot meet without one of us present. But I’ve gone over the original treaty. It does not stipulate that the family’s representative must be a vampire.” Baldwin shook his head. “If I didn’t know better, I would think that Philippe foresaw this day and planned it all.”

“What do you expect Auntie to do?” Gallowglass demanded. “She’s may be a weaver, but she’s no miracle worker.”

“Diana needs to remind the Congregation that this is not the first time complaints have been made about a vampire in Chelm,” Baldwin said.

“The Congregation has known about Benjamin and done nothing?” I couldn’t believe it.

“They didn’t know it was Benjamin, but they knew that something was wrong there,” Baldwin replied. “Not even the witches cared enough to investigate. Knox may not be the only witch working with Benjamin.”

“If so, we’ll not get far in Chelm without the Congregation’s support,” Hamish said.

“And if the witches there have been Benjamin’s victims, a group of vampires will need the Chelm coven’s blessing if we want to succeed, as well as the Congregation’s support,” Baldwin added.

“That means persuading Satu Järvinen to side with us,” Sarah pointed out, “not to mention Gerbert and Domenico.”

“It is impossible, Baldwin. There is too much bad blood between the de Clermonts and the witches,” Ysabeau agreed. “They will never help us save Matthew.”

“Impossible n’est pas français,” I reminded her. “I’ll handle Satu. By the time I join you, Baldwin, you’ll have the full support of the Congregation’s witches. The daemons’, too. I make no promises about Gerbert and Domenico.”

“That’s a tall order,” Gallowglass warned.

“I want my husband back.” I turned to Baldwin. “What now?”

“We’ll go straight to Matthew’s house in Venice. The Congregation has demanded that you and Matthew appear before them. If they see the two of us arrive, they’ll assume I’ve done their bidding,”

Baldwin said.

“Will she be in any danger there?” Marcus asked.

“The Congregation wants a formal proceeding. We will be watched—closely—but no one will want to start a war. Not before the meeting is over, at any rate. I will go with Diana as far as Isola della Stella where the Congregation headquarters, Celestina, is located. After that, she can take two attendants with her into the cloister. Gallowglass? Fernando?” Baldwin turned to his nephew and his brother’s mate.

“With pleasure,” Fernando replied. “I haven’t been to a Congregation meeting since Hugh was alive.”

“Of course I’m going to Venice,” Gallowglass growled. “If you think Auntie’s going without me, you’re daft.”

“I thought as much. Remember: They can’t start the meeting without you, Diana. The council chamber’s door won’t unlock without the de Clermont key,” Baldwin explained.

“Oh. So that’s why the key is enchanted,” I said.

“Enchanted?” Baldwin asked.

“Yes. A protection spell was forged into the key when it was made.” The witches who had done it were skilled, too. Over the centuries the spell’s gramarye had hardly weakened at all.

“The Congregation moved into Isola della Stella in 1454. The keys were made then and have been handed down ever since,” Baldwin said.

“Ah. That explains it. The spell was cast to ensure that you don’t duplicate the key. If you tried, it would destroy itself.” I turned the key over in my palm. “Clever.”

“Are you sure about this, Diana?” Baldwin studied me closely. “There’s no shame in admitting you’re not ready to confront Gerbert and Satu again. We can come up with another plan.”

I turned and met Baldwin’s gaze without flinching.

“I’m sure.”

“Good.” He reached for a sheet of paper that was waiting on the table. A de Clermont ouroboros was pressed into a disk of black wax at the bottom, next to Baldwin’s decisive signature. He handed it to me. “You can present this to the librarian when you arrive.”

It was his formal recognition of the Bishop-Clairmont scion.

“I didn’t need to see Matthew with that girl to know he was ready to lead his own family,” Baldwin said in answer to my amazed expression.

“When?” I asked, unable to say more.

“The moment he let you intervene between us in the church—and didn’t succumb to his blood rage,” Baldwin replied. “I’ll find him, Diana. And I’ll bring him home.”