"How so?"

"We decipher the riddle."

"But that could take days."

Vigor glanced over his shoulder. "Not if I've already solved it."

He waved for the pad of paper and flipped to a new blank page. "Let me show you."

Then he did the oddest thing. He wet his finger in his espresso and dampened the bottom of his tiny cup. He pressed the cup upon the paper, leaving a perfect ring of coffee stain on the blank page. He repeated it again, applying a second ring, this one overlapping the first, forming roughly a snowman shape.

"The full moon mating with the sun."

"What does this prove?" Gray asked.

"Vesica Pisces," Rachel said, her face dawning with understanding.

Vigor grinned at her. "Did I ever tell you how proud I am of my niece?"

7:02 P P.M.

RACHEL DIDN'T like abandoning their Carabinieri escort, but she understood Uncle Vigor's excitement. Her uncle had insisted they take alternate transportation to investigate the new lead. like abandoning their Carabinieri escort, but she understood Uncle Vigor's excitement. Her uncle had insisted they take alternate transportation to investigate the new lead.

So she had called in to the station and recalled the patrol cars. She had left a cryptic message with General Rende that they all had an errand to run. This last was upon Gray's suggestion. He thought it best not to broadcast their destination. Not until they could investigate further.

The fewer people who knew of their discovery, the better.

So they sought alternate transportation.

Rachel followed Gray's broad back down to the rear of the public bus. Kat and Monk held a row of seats open. The air conditioning clanked, and the engine rattled the floorboards as the bus left the curb and shouldered into traffic.

Rachel climbed into a seat with Gray. Their row of seats faced Monk, Kat, and Uncle Vigor. Kat looked especially stern. She had argued for proceeding to the Vatican and securing an escort first. Gray had overruled her. She looked unsettled by this decision.

Rachel eyed Gray beside her. Some new resolve seemed to have hardened in him. It reminded her of his att.i.tude atop the fiery spire in Cologne, a certainty of manner. His eyes shone with a determination that had disappeared after the first attack. It was back now...and it scared her slightly, made her heart beat faster.

The bus rumbled into traffic.

"Okay," Gray said, "I've taken you at your word that this side excursion is necessary. Now how about a bit of elaboration?"

Uncle Vigor raised a palm, conceding. "If I had gone into detail, we would've missed our bus."

He opened the pad again. "This shape of overlapping circles can be seen throughout Christendom. In churches, cathedrals, and basilicas around the world. From this one shape, all of geometry flows. For example." He turned the picture horizontal and shaded the lower half with the edge of his palm. He then pointed to the intersection of the two circles. "Here you can see the geometric shape of the pointed arch. Almost all Gothic windows and archways bear this shape."

Rachel had been given the same lecture as a child. One couldn't be related to a Vatican archaeologist without knowing the importance of those two joined circles.

"It still looks like a couple of doughnuts smashed together to me," Monk said.

Vigor righted the picture back around.

"Or like a full moon mating with the sun," her uncle said, bringing up the stanza from the cryptic text. "The more I consider those lines, the more layers I keep coming across, like peeling an onion."

"What do you mean?" Gray asked.

"They buried this clue within the Egyptian Book of the Dead Book of the Dead. The very first book to refer to manna manna. Later Egyptian texts begin to refer to it as 'white bread' and such. It's as if to find whatever the alchemists hid, you had to start at the beginning. Yet the very answer to this first clue also traces back to the first era of Christianity. Multiple beginnings. Even the answer itself implies multiplication. The one becoming many."

Rachel understood what her uncle meant. "The multiplication of the fishes."

Vigor nodded.

"Is anyone going to explain it to us novices?" Monk asked.

"This conjoining of circles is called Vesica Pisces, Vesica Pisces, or Vessel of the Fishes." Vigor leaned down and shaded the intersection to reveal the fishlike shape rested between the two circles. or Vessel of the Fishes." Vigor leaned down and shaded the intersection to reveal the fishlike shape rested between the two circles.

Gray peered closer. "It's the fish symbol that represents Christianity."

"It is the first symbol," first symbol," Vigor said. "'When the full moon mates with the sun, it is born.'" Her uncle tapped the fish. "Some scholars believe the fish symbol was used because the Greek for fish, Vigor said. "'When the full moon mates with the sun, it is born.'" Her uncle tapped the fish. "Some scholars believe the fish symbol was used because the Greek for fish, ICHTHYS, ICHTHYS, was an acronym for was an acronym for Iesous Christos Theou Yios Soter, Iesous Christos Theou Yios Soter, or Jesus Christ, the Son of G.o.d, the Savior. But the truth lies here, between these circles, locked in sacred geometry. You'll often find these locked circles in early paintings with the Christ child resting in the center junction. If you turn the form over on its side, the fish becomes a representation of female genitalia and a woman's womb, where the baby Jesus is painted. or Jesus Christ, the Son of G.o.d, the Savior. But the truth lies here, between these circles, locked in sacred geometry. You'll often find these locked circles in early paintings with the Christ child resting in the center junction. If you turn the form over on its side, the fish becomes a representation of female genitalia and a woman's womb, where the baby Jesus is painted.

"It is for this reason that the fish represents fertility. To be fruitful and multiply." Vigor glanced around the group. "As I said, there are layers upon layers of meaning here."

Gray leaned back. "But how does this lead us anywhere?"

Rachel was curious, too. "There are fish symbols all over Rome."

Vigor nodded. "But the second line that reads, 'It is born eldest eldest.' Plainly it's directing us to the oldest representation of the fish symbol. That would be found in the Crypt of Lucina in the Catacombs of Saint Callistus."

"That's where we're heading?" Monk asked.

Vigor nodded.

Rachel noted Gray was not satisfied. "What if you're wrong?" he asked.

"I'm not. The other stanzas in the text hint at it, too...once you solve the Vesica Pisces Vesica Pisces riddle. Look at the next line. 'Where it drowns, it floats in darkness.' A fish can't drown, not in water, but it can in earth. And the mention of darkness. It all points to a crypt." riddle. Look at the next line. 'Where it drowns, it floats in darkness.' A fish can't drown, not in water, but it can in earth. And the mention of darkness. It all points to a crypt."

"But there are many crypts and catacombs throughout Rome."

"But not many with two two fishes, twins to each other," Vigor said. fishes, twins to each other," Vigor said.

Gray's eyes brightened with understanding. "Another clue, from the last stanza. 'The Twin waits for water.'"

Vigor nodded. "All three stanzas point to one place. The Catacombs of Saint Callistus."

Monk settled back to his seat. "At least it's not a church this time. I'm tired of getting shot at."

7:32 P P.M.

VIGOR SENSED they were on the right track. they were on the right track.

Finally.

He guided the others through Porta San Sebastiano, one of the city wall's most striking gates. It also served as the gateway to the parklands that surrounded the Appian Way, a preserved section of the famous ancient Roman road. Immediately past the gates, however, stood a series of dilapidated mechanics' workshops.

Vigor dismissed the ugliness of these junkyards by directing attention ahead. At a fork in the road rose a small church. "The Chapel of Domine Quo Vadis," he said.

His only real audience was Kat Bryant. She strode alongside him. Kat and Gray seemed to have had a falling-out. The others followed behind. It was good to have this moment with Kat. It had been three years since they had shared a role in cataloguing evidence against a n.a.z.i war criminal, living in rural New York. The target had been trading in stolen artwork in Brussels. It was a long, convoluted investigation, requiring subterfuge on both their parts. Vigor had been most impressed with the young woman's ability to slide into any role as easily as changing shoes.

He also knew the pain she had experienced recently. Though she was a good actress, hiding her feelings well, Vigor had spent enough time serving his flock as priest, confessor, and counselor to recognize someone still grieving. Kat had lost someone close to her heart and had not healed yet.

He pointed to the stone church, knowing there was a message for Kat within those walls. "The chapel here was built at the site where Saint Peter, fleeing the persecution of Nero, beheld a vision of Jesus. Christ was heading into Rome, while Peter was running out. He asked those famous words, Domine, quo vadis Domine, quo vadis. 'Lord, where are you going?' Christ replied he was heading back into Rome to be crucified again. Peter then turned back to face his own execution."

"Ghost stories," Kat said without malice. "He should've run."

"Ever the pragmatist, Kat. But you of all people should know that sometimes one's own life is less important than the cause. We all have a terminal disease. We can't escape death. But as the good works in our life celebrate our time here, so too can our deaths. To lay one's life down in sacrifice should be honored and remembered."

Kat glanced to him. She was sharp enough to understand the tack of the conversation.

"Sacrifice is a final gift we mortals can give in life. We should not squander such a generous gift with misery, but with respectful appreciation, even joy for a life fully lived to its end."

Kat took a deep breath. They crossed before the small chapel. Her eyes studied it-though Vigor suspected she looked just as intently inward.

"There can be lessons even in ghost stories," Vigor finished, and guided the group down the fork to the left.

Here the road turned to cobbles of volcanic stone. Though the stones were not original to the Roman road that once led out from the gates of the city all the way to Greece, it was a romantic approximation. Slowly the way opened around them. Green swards of hillsides opened in parklands, dotted with occasional sheep and shaded by umbrella pines. Crumbling lines of walls crisscrossed the landscape, along with the occasional tomb.

At this hour, with most of the attractions closed and the sun near to setting, they had the Appian Way to themselves. An occasional stroller or bicyclist nodded to him, noting his collar. "Padre," "Padre," they would mumble and continue past, glancing back at the road-weary group of backpackers he led. they would mumble and continue past, glancing back at the road-weary group of backpackers he led.

Vigor also noted a few scantily clad women lounging at roadside spots, along with some seemlier-looking figures. After dark, the Appian Way became a roost to prost.i.tutes and their ilk, and often proved dangerous to the average tourist. Brigands and robbers still prowled the ancient road, as they had the original Appian Way.

"It's not much farther," Vigor promised.

He headed through an area of vineyards, green vines tied to wood and wire, that traversed the gently sloping hills. Ahead appeared the courtyard entrance to their destination: the Catacombs of Saint Callistus.

"Commander," Kat asked, dropping back, "shouldn't we at least scout the area first?"

"Just keep your eyes open," he answered. "No more delays."

Vigor noted the firmness in the man's voice. The commander listened, but he seemed less willing to bend. Vigor was unsure if this was good or bad.

Gray waved for them to proceed.

The subterranean cemetery had closed at five o'clock, but Vigor had called the caretaker and arranged this special "tour." A pet.i.te snowymaned gentleman in gray coveralls stepped out of a sheltered doorway. He hobbled over, using a wooden shepherd's crook as a cane. Vigor knew him well. His family had been sheepherders of the surrounding campagna campagna going back generations. He held a pipe firmly between his teeth. going back generations. He held a pipe firmly between his teeth.

"Monsignor Verona," he said. "Come va?" "Come va?"

"Bene grazie. E lei, Giuseppe?"

"I'm fine, Padre. Grazie Padre. Grazie." He waved toward the small cottage that served as his homestead while watching over the catacombs. "I have a bottle of grappa. I know how you like a bit of the grape. From these hills."

"Another time, Giuseppe. The day grows late and we must be about our business with much haste, I'm afraid."

The man eyed the others as if they were to blame for the rush, then his eyes caught on Rachel. "It cannot be! Piccola Rachel Piccola Rachel...but she is not so little anymore."

Rachel smiled, clearly delighted to be remembered. She hadn't visited here with Vigor since she was nine years old. Rachel quickly hugged him, kissing him on the cheek. "Ciao, Giuseppe." Giuseppe."

"We must raise a cup to piccola piccola Rachel, no?" Rachel, no?"

"Perhaps when we finish our business below," Vigor pressed, knowing the man, lonely here in his cottage, only wanted a bit of company.

"Si...bene..." He waved his crook toward the doorway. "It is open. I will lock after you. Knock when you come up and I will hear." He waved his crook toward the doorway. "It is open. I will lock after you. Knock when you come up and I will hear."

Vigor led them to the gateway to the catacombs. He pulled open the door. He waved the others through the threshold, noting that Giuseppe had left the string of electric lights lit. The staircase descended ahead of them.

As Monk stepped through with Rachel, he glanced back to the caretaker. "You should introduce that guy to your grandmother. They'd hit it off, I bet."

Rachel grinned and followed the stocky man inside.

Vigor closed the door behind him and took the lead again, heading down the stairs. "This catacomb is one of Rome's oldest. It was once a private Christian cemetery, but it spread out when some of the popes chose to be buried at this site. It now covers ninety acres and descends in four levels."

Behind him, Vigor heard the door lock snap closed. The air grew danker as they descended, rich with the smell of loam and seeping rain-water. At the foot of the stairs, they reached a vestibule with loculi loculi cut into the walls, horizontal niches for bodies to be laid to rest. Graffiti etched the walls, but it was not the work of modern vandals. Some of the inscriptions dated back from the fifteenth century: prayers, laments, testimonials. cut into the walls, horizontal niches for bodies to be laid to rest. Graffiti etched the walls, but it was not the work of modern vandals. Some of the inscriptions dated back from the fifteenth century: prayers, laments, testimonials.

"How far in do we have to go?" Gray asked, stepping next to Vigor. There was barely room for two to walk side by side as the way narrowed from here. The commander eyed the low ceilings.

In here, even those who didn't suffer from claustrophobia found these crumbling subterranean necropolises unnerving. Especially now. Deserted and empty.

"The Crypt of Lucina lies much deeper. It's located in the most ancient area of the catacomb."

Galleries branched off from here, but Vigor knew the way and headed to the right. "Stay close," he warned. "It's easy to get lost in here."

The way narrowed even more.

Gray turned. "Monk, keep a watch on our rear. Ten paces. Stay in sight."

"Got it covered." Monk freed his shotgun.

Ahead, a chamber opened. Its walls were pocked with larger loculi loculi and elaborate and elaborate arcsololia, arcsololia, arched gravesites. arched gravesites.

"The Papal Crypt," Vigor announced. "It is here sixteen popes were laid to rest, from Eutychia.n.u.s to Zephyrinus."

"From E to Z," Gray mumbled.

"The bodies were removed," Vigor said, delving deeper, pa.s.sing through the Crypt of Cecelia. "From about the fifth century, the outskirts of Rome were plundered by a series of forces. Goths, Vandals, Lombards. Many of the most important personages buried here were moved into churches and chapels inside the city. In fact, the catacombs were so emptied out and abandoned that by the twelfth century they were completely forgotten, and were not rediscovered until the sixteenth century."