Mia shook her head. “No—it wasn’t a gurgling sound, nor a train. More like a zephyr—a singing wind.” Wide, liquid eyes moved from him to Jersey and back again. “You don’t hear it?”

“Does the cat hear this strange wind or does Mia?” Exeter probed, gently.

Mia chewed her lip. “I’m not sure.” He thought he knew the answer but signaled Jersey to push on.

“We’re almost there.” Jersey swung the luminous sword forward, and they followed after him. The narrow passage gradually widened into a large chamber. They found themselves standing before a stone portal at the entrance to the ossuary. Above the doorway there was an inscription: Arrête! C’est ici l’empire de la Mort. Jersey read the words aloud.

Mia translated, “Halt! This is the Empire of Death.”

They entered a cavern lined with carefully arranged human bones. Bones heaped high behind retaining walls made up of femurs and tibias, skulls and mandibles. Some of the arrangements were artistic in nature: a heart-shaped outline in one wall, a cross of skulls on the opposite side of the room. A number of intricate designs were fashioned using skulls surrounded by a pattern of stacked femurs and tibias.

They stepped gingerly at first, and then more rapidly, as Jersey ushered them through one connecting cavern after another. Mia turned to back to him. “Dear God, Exeter—so many lost souls.”

“Millions, I’m afraid.” As if his answer wasn’t grim enough, Jersey pointed to a placard mounted on a wall that estimated the number of dead. Near six million. They entered a round room circling a huge central pillar carefully crafted out of an arrangement of bones.

Jersey pointed the end of his blade at one rusty gate, then another. Both blocked passages led to other parts of the catacombs. Signs posted on the iron bars warned of possible cave-ins—that the passages beyond were either under renovation or unsafe to navigate. The Nightshade looked to Exeter. “The next tunnel is crucial if we are to meet up with the others.”

Exeter opened a satchel strung over his shoulder and removed a tin with half the heat-seeking bugs. Mia helped Exeter spread the inert bugs around the cavern. “What did you do with my cinder toffees?” Mia asked suspiciously.

He searched in another pocket and unwrapped a pocket square. Two large pieces of the honeycombed toffee lay in his palm. Before she could reach for a piece he pocketed the handkerchief. “If we get lost down here this could be our only sustenance until we’re discovered by either Tim Noggy or Prospero.”

“I’m not about to get lost down here.” Mia’s hand plunged into his pocket and retrieved the candy. She selected the smallest piece and offered up the other.

Nodding toward one of the gates, Jersey popped the honeycomb in his mouth. “Somewhere south of this room, we need to make a right turn.”

Exeter folded up his map. “No matter what, we maintain a southwest heading. If a passage takes us off course, we double back.” Leveling his compass, Exeter confirmed the direction Jersey was pointing.

Mia sighed. “Worst case, Ping will find us.”

Jersey fired up his dagger and made short work of the gate lock, ushering them into the next passage. Up until this point the tunnels had been tall enough for even Jersey and Exeter to traverse upright—now there were long stretches of low ceilings. Jersey frequently called out, “Watch your head.”

As the passage lowered and narrowed, Mia began to appear agitated. Twice she stopped and whispered, “Shush!”

Jersey slowed. “We’ve got a dead end ahead.”

“Shush!” Mia’s harsh whisper was more adamant this time—enough to warrant a long silence. A moaning sigh—something decidedly unnatural—whimpered through the cracks and crevices of the limestone walls.

Mia’s eyes were large and round. “Did you hear that?”

Exeter looked up at Jersey who nodded. “I say we track back to the gate and look for another tunnel south.”

The singsong voice whispered again. Exeter whirled around, looking for a being or face. He’d even settle for a smile—but found none.

A second wave of hushed quavers filled the air. “Circles-ss-s, circles-s-s-s—you move in circles.” The musical, airy voice hissed. He checked his compass again. “The needle is spinning.” Jersey and Mia both leaned in for a closer look.

Exeter drew on his gut instinct, something he had learned to trust when confronted by the supernatural. “Talk to the wind, Mia.” He smiled softly and nodded to encourage her.

She scanned the rock walls on both sides of the passage. “Who speaks?”

“Who-o-o asks-s-s-s?” the voice sputtered and hissed.

“You talk as though you were out of breath, but you are made of air—you are the wind.”

“Alas-alas-alas-s-s-s, not wind . . . per s-s-s-se. I am the last breath of the souls who are buried here.”

“Oh dear,” Mia exhaled a sigh of solidarity. “Would you tell us, please, which way to go from here?”

“That would depend on wh-wh-where,” wafted the whisper, “you were going.”

“We make our way southwest to join our friends,” said Mia.

“Then, you must s-s-s-top moving in circles-s-s-s. If you continue to circle, no matter which way you journey, you will only return to me.”

Exeter frowned; this strange wind whispered in riddles.

“No, that won’t do—we need to get somewhere,” Mia insisted adamantly.

“Oh, you’re s-s-s-sure to do that,” mocked the wind. “That is—if you are contrary enough.”

Mia checked with Exeter. “Contrary?” she mouthed silently. He shrugged. Mia must have felt as though she was getting nowhere, because she tried another tack. “What sort of beings live here about?”

“In that direction,” a breezy zephyr blew by their noses, “lives an old rock troll and in the other”—the whisper abruptly reversed course and rushed down the passage they’d just come from—“there is a magician. I don’t advise you visit either one—they’re both mad.”

A whimpering moan whirled into a cyclone of wind, tossing up a screen of dust particles. Mia squinted—they all did—as sand and dirt swirled around them. In warning, Jersey pointed his sword at the twister. Using all the seeing power he could muster, Exeter made out the shredded robe of an ethereal being. The creature turned tail and vanished down the narrow corridor.

Exeter suspected a deception—something whimsical and unthreatening—to distract them. He broke the silence. “What kind of down-the-rabbit-hole trickery was that?”

Jersey slashed his sword as he started down the corridor. “One of Prospero’s hirelings. We’d better move on—in a hurry.”

He checked his compass. “Magnetic north has returned.”

“Humor me for a moment, gentlemen.” Mia blew a few strands of hair off her face. “What if she . . . the entity . . . was trying to be helpful?”

“She?” He and Jersey asked in unison.

“Whatever it was, it felt like a she, though I suppose it might have been a he.” Mia shot them a bug-eyed “pay attention” look. “When I said—‘but we need to get somewhere,’ the wind answered—”

“If you’re contrary enough.” Exeter repeated the zephyr’s words.

“Exactly!” Mia’s eyes brightened. “What if your compass is not reading true north? What if, in effect, we have been traveling northeast, instead of southwest?”

Exeter’s gaze rose from the instrument in his palm. “You’re suggesting we follow a course contrary to the compass.”

Mia pivoted in place, peering into the blackness of the crudely carved passage. “It’s possible we missed a much smaller tunnel—one that heads in a northeast direction.”

“Why don’t you two have a look about,” Jersey grunted. “I’ll double back to the round room—get to work on the next gate.”

Exeter reached in his coat pocket and produced the experimental torch. He toggled the switch. Nothing. “Hold on, Jersey.” He slapped the metal cylinder against his palm and a circular beam of light spread across the tunnel. “Open every gate you find, and keep a sharp eye,” he called after him, “we could be walking straight into a trap.”

“May I?” Mia tugged on the torch.

Exeter didn’t let go—not at first. He just wanted to take a moment and admire her. That was rather brilliantly intuitive, Mia.

No compliments—not yet. She smiled up at him. “If we rendezvous with Tim Noggy you can buy me breakfast at the crêperie on Boulevard Saint-Michel.”

“It would be my pleasure.” She had read his thoughts, again. There was an intimacy in knowing another’s thoughts—as well as a disturbing invasion of privacy. Exeter released the torch, and followed close behind Mia as she swept the beam across the corridor, from one wall to another.

Taking their time, they explored a few smaller tunnels that either grew too small for passage or turned back on themselves. Up ahead, the spit and hiss of Jersey’s sword reverberated through the passageway. Mia stopped to examine a makeshift scaffolding constructed over a chasm. Joining her, he peered into the depths of the pit. Some sort of cave-in had collapsed the floor. When combined, both maps had shown quarry tunnels dug at different depths—he sensed another passage directly below.

Mia glanced back at him. “I’d like to have a look under these boards.”

They found an open spot that led down into the cavern—not steps exactly, more like a few toeholds. Using potent energy, Exeter jumped first and waved her down. Following right behind him, she lost her footing and began to slide.

Exeter brought her down the rest of the way, wrapping his arms around her possessively. “You might have used a bit of relic dust and champagne,” he murmured. She nuzzled his neck and purred—yes, he was quite sure of it. “And how is pussy this evening?”