Mercy grinned. “Quid tibi, mors, faciam quae nulli parcere nosti?” “You speak Latin?” Tripp asked disbelievingly.

Mercy’s smile faded, and she cast Tripp a look of pure contempt. “When I have to. Death words work better in dead languages, okay?”

Alex was surprised at the edge in Mercy’s voice, but Tripp just shrugged.

“If you say so.”

“What does it mean?” asked Turner.

“What am I going to do with you, Death, who spares no one? ” quoted Mercy. “It’s funny, right? Like Death is a bad party guest.”

“I’m all for Latin,” said Alex, “but death words aren’t going to help against a demon.”

“I have something in mind for that,” said Dawes.

“Salt armor,” Mercy said.

Dawes beamed at her. “Exactly.”

Alex was embarrassed to feel a pang of jealousy at that proud look, another unpleasant reminder that she was the interloper here.

“What happens when the library closes?” asked Turner.

“We walk the stations of the Gauntlet together.” Dawes gestured to the sideboard. “Mercy will set the metronome ticking. The rhythm has to remain uninterrupted until the ritual is complete.”

That didn’t make much sense to Alex. “I don’t think they had metronomes in Thonis.”

“No,” agreed Dawes. “In times past, a whole group of people would have stood sentinel and kept the beat with drums or other instruments. But we don’t have a group and we don’t know how long we’ll be. We can’t risk Mercy getting fatigued or interrupted.” Tick tick tick. The bomb waiting to go off.

“We’ll begin outside at the scribe,” Dawes continued, “and mark the entrance with our mingled blood.”

Turner shook his head. “This is some satanic shit.”

“It’s not,” said Dawes defensively. “The blood binds us and should wake the Gauntlet.”

“So we’ll know we’re on the right path?” Alex asked.

Dawes gnawed on her lower lip. “That’s the idea. Each pilgrim has a designation that determines the order we use to walk the Gauntlet. Soldier first, then scholar, then priest, then prince.” She cleared her throat. “I believe I should take the role of scholar. Given Turner’s religious leanings, he can take the office of priest.”

“I can be the soldier,” Tripp offered.

“You’re the prince,” said Alex. “I’m the soldier. I’ll walk first.”

“That means you’ll also be the one to close the circuit,” warned Dawes.

“You’ll walk that final stretch alone.”

Alex nodded. That was the way it should be. She was the one who had let the hellbeast consume Darlington in that basement. She’d be the one to close the circle.

“By then,” Dawes said, “we’ll all have taken our positions in the courtyard. Each of the four doorways will be marked with blood. We’ll need

a signal so we can all begin the walk to the center of the courtyard at the same time.” She set down a metal disc.

“A pitch pipe?” asked Mercy.

Dawes nodded. “It was enchanted sometime in the fifties to ensure perfect harmony. I’m hoping it will help us stay in sync if things get … difficult.”

Alex didn’t want to dwell too long on what that might mean. “We’re sure the courtyard is the spot?”

Dawes pointed to a series of Post-its she’d laid out on a plan of the Selin Courtyard. “Four doorways. Four pilgrims. Four compass points. And the inscriptions can’t be a coincidence. Remember the Tree of Knowledge? This is engraved above the stone sundial on the librarian’s door. Ignorance is the curse of God. Knowledge the wing wherewith we fly to heaven. ” “Henry VI,”

said Mercy and glanced at Alex with a grin.

Alex smiled back. “More Shakespeare.”

“There’s also this.” Dawes held up a photo of a stone grid of numbers.

“Sudoku?” asked Tripp.

Dawes looked at him as if she wasn’t sure whether to put him to bed with a hot water bottle or hit him with a shovel. “It’s the magic square from Albrecht Dürer’s Melencolia. Every direction you add the numbers, the sum is always the same. I think it’s a gesture toward containment.”

“A perfect puzzle for a demon to get caught up in,” Alex said.

“Exactly. And of all the details from Dürer’s works, it has no real reason to be in this courtyard.”

“What’s at the center?” Turner asked. “What are we all marching toward?”

Mercy wrinkled her nose. “There’s a fountain, but it’s not much to look at. More of a big square basin with some cherubs stuck on the corners.”

“It was added later,” Dawes said. “After the library was built. Because something was seeping up through the stones.” Silence settled over the room.

Turner scrubbed a hand over his head. “Fine. We get to the middle. Then what happens?”

Now Dawes hesitated. “We descend. I don’t know what that entails. Some people describe hallucinations and an actual sensation of falling, others describe a complete disconnect from the body and a feeling of flight.”

“Sweet,” said Tripp.

“But that could be because of the datura.”

“That’s a poison,” said Turner. “Had a case where a woman was growing it in her backyard, putting it in lotions and ointments.”

“It does have medicinal uses,” said Dawes. “It just needs a steady hand.”

“Sure,” said Turner. “Are you going to tell them its other name?”

Dawes looked down at her notes and mumbled, “Devil’s trumpet. The pilgrims are anointed with it before they begin. It loosens the soul’s tether to this world. We can’t cross over without it.” “And then we die,” said Alex.

Tripp gave a nervous laugh. “Metaphorically, right?”