She searched the cavernous length of the nave. People, frightened by the gunplay, cowered in corners or shifted in maddened tides of confusion and panic. She had to find Gray and Vigor.

Sirens sounded in the distance.

A hand snagged her shirt. Reflexively, she jabbed a pistol into ribs.

Her target didn't flinch. "Seichan, what happened?"

It was Gray, his face drawn and pale.

"Gray ... we have to get out of here. Now. Where's the monsignor?"

He pointed toward a neighboring stairwell. Vigor kept half hidden at its entrance and watched the crowd.

Seichan herded Gray over to him.

The monsignor stared back at the arched doorway, his eyes wounded with grief. "Nasser shot him. Shot Balthazar."

"No," Seichan said, killing any misconception. "I did."

Vigor backed a step. Gray swung around.

"He was working with Nasser," Seichan explained.

Vigor's voice turned angry. "How can . . . ?"

"I have photos from two years ago. Nasser and Balthazar together. Money changed hands." She fixed Vigor with a hard stare. "He's been working with him all along."

Seichan read the continuing disbelief. She hardened her voice. "Monsignor, who called your attention to the inscription in the Tower of Wind?"

Vigor glanced toward the doors, toward the dead man out of sight.

"Before involving you both," Seichan pressed, "Nasser and I were playing cat and mouse throughout Italy, searching for the first bits of the angelic puzzle. No one was supposed to discover my invisible mark in the Vatican until I called you, alerted you to search the tower's closet with an ultraviolet light. Do you think your friend just accidentally stumbled upon it?"

"He said . . . one of his students . . ."

"He was lying. Nasser told him. The bastard followed the same trail I did. Used Balthazar to recruit you into solving the riddle."

Vigor sank to the stairs, covering his face.

Seichan turned to Gray. He stood a step away, eyes glazed, reconfiguring all the morning's events in light of the revelation. He must have sensed Seichan's attention.

"Then Nasser knew we were trying to betray him," Gray said. "He knew we had the first key. He knows everything."

"Not necessarily." Seichan pulled Vigor up by the shoulder and shoved Gray toward the church. "It was why I had to take him out. I don't think he had the time to call Nasser after he left you. I took him out before he got the chance and made things worse."

"Worse?" Gray stopped, refusing to move, his eyes furious. "You could have captured him. We could have used him against Nasser. There were a thousand options!"

"All of them too risky!" Seichan stepped closer, walking into the fire. "Get this through your thick skull, Gray. Nasser's plan, our plans . . . they're all screwed. It's clean slate time here. And we have to act now."

His face darkened as anger boiled up. Even his eyes turned stormy. "When the bastard finds out what you did . . . what we did . . . you just got my parents killed!"

She cut him off with a resounding slap to the face, knocking him back a step. Stunned, he lunged at her. She didn't resist. He collared her. His other hand a fist.

She kept her voice calm against his storm. "With that bastard dead, we have a small window of confusion here. We must take advantage of it."

"But my folks—"

She kept her voice even. "Gray, they're already dead."

The fist tangled in her shirt trembled. His face constricted tight, red and agonized. His eyes searched her, needing someone to blame.

"And if they're not dead," she continued, "if he's keeping them alive as extra insurance, then we have only one hope here."

Gray's hand dropped from her throat but remained clenched.

"We'll need a big bargaining chip," she continued. "Equal to the weight of your parents' lives."

In his eyes, she could see the rage beginning to subside, the tide going out, the words finally sinking in. "And the second key alone won't do it."

She shook her head. "We need to go silent. Have Vigor pull his cell phone battery so that it's not tracked."

"But how will Nasser reach us?"

"It's time we took that control from him."

"But when he tries to call us ... ?"

"Nasser will be furious. He may hurt one, or both of your folks, maybe even kill one. But until he finds us, he'll keep one alive. He's not a fool. And that is our only hope."

Vigor's phone began to ring. Everyone froze a breath. Then Vigor slipped it out of his pocket. He glanced to the caller ID, swallowed, and passed it to Gray.

He took it. "Nasser," he confirmed.

"Speak of the devil," Seichan hissed. "One of the snipers must have called him. Needing to get further instructions. It's probably the only reason they haven't stormed the place already. Killing Balthazar caught them off guard. This is the only window we have."

Gray stared down at the phone.

Seichan waited.

How strong was this man?

2:04 P.M.

Gray's fingers refused to move, clamped around the phone.

It vibrated and rang again.

He could almost feel the fury emanating out of it, an anger ready to be unleashed against his mother and father. He wanted desperately to answer it: to scream, to beg, to curse, to bargain.

But he had no leverage.

Not yet.

"Nasser must still be in midflight," Gray finally mumbled to the phone.

"Due to touch down in five hours," Seichan agreed.

Gray let a coldness wash through him, but his fingers tightened harder. "Up in the air, he'll hesitate to make any major decisions. He'll wait until his feet are on the ground before making a final assessment."

"And if he hasn't heard from you by then .. ."

Gray couldn't say the words. He only nodded his confirmation. Nasser would kill his parents. He won't wait any longer than that. He'll punish Gray and move on to a new strategy.

Five hours.

"We'll need more than the second key we found here," he said. "More than even the third key."

Seichan nodded.

Gray stared up at Seichan. "We'll need to have solved the obelisk's riddle. We'll need Marco's map."

Seichan simply stared, waiting.

Gray knew what he had to do. He flipped the phone over. With fingers numb and uncooperative, he fumbled with the battery in back.

Vigor stepped up and covered his palm over Gray's fingers. "Are you sure, Gray?"

He lifted his eyes. "No . .. I'm not. I'm not sure of a damn thing." He slipped his hands free of the monsignor's and peeled the battery off the phone, cutting the last ring in half. "But that doesn't mean I won't act."

Gray turned to Seichan. "What now?"

"You've just thrown down the gauntlet. Nasser will be calling his henchmen. We've got maybe a minute or two." She pointed into the depths of the church. "This way. Kowalski's got a car. He'll meet us out at the east exit."

She led them down the nave. People milled, unsure, voices echoed. Sirens closed down upon their location. Seichan fished something out of her pocket.

"Nasser must have snipers at that exit, too," Gray said, striding up to her.

Seichan held out her palm. "Concussive grenade. A flash-bang. We'll detonate it in the center. As everyone goes rushing out the exits . . . out we'll go, too."

Gray frowned.

Vigor voiced his concern as they circled past a crowd of schoolchildren, all wide-eyed and fearful, clutched in a group. "If the snipers see any of us, they'll open fire. On the crowd."

"No other way." Seichan sped faster. "We'll have to take the chance. Nasser's men may already be coming—"

A gunshot cracked loudly in the church.

Gray felt something whine past his ear. A bit of wall mosaic blasted in a shower of gold.

The crowd panicked, fleeing in all directions.

Vigor was knocked to a knee. Gray dragged him up as a second shot sparked against a marble column. The blast echoed.

Staying low, the trio fled to the side and down the length of the nave. As they reached the center, Seichan prepared to pure the pin on the grenade.

Gray grabbed her hand, restraining her. "No."

"It's the only way. There could be more shooters ahead of us. We'll need to trample with them to reach the exit."

And if we're spotted amid the crowd, he thought, how many innocent people will be killed?

He pointed. "There's another way."

Still holding his hand clamped to hers, he led them all to the south side, toward the wall of scaffolding he had scaled earlier.

"Up!" he said.

However, there remained one obstacle.

The scaffolding guard had not fled his post. He remained crouched behind a wooden barrier, his rifle up, ready to shoot.

Gray snatched the grenade out of Seichan's fingers, pulled the pin, and tossed the bomb behind the barrier. "Close your eyes!" he yelled at Vigor, pulling the monsignor down. "Cover your ears."

Seichan crouched, her head wrapped in her arms.

The explosion felt like a kick to the gut. A sonic boom trapped in stone. A flash seared through Gray's lids, even with his head turned away.

Then it was over.

Gray yanked Vigor up. Screams echoed, sounding muffled through the residual ring in his ears. He rushed toward the massive scaffolding. The crowds parted, fleeing toward the east and west exits.

But they weren't going with them.

At the scaffolding, the guard was down, dazed on his back, moaning.

He'd have a bad headache, but he'd live.

Gray took his rifle and waved Seichan and Vigor up the scaffolding staircase. They'd have to move fast. The stampede would slow the shooters, but only for so long.

He clambered up after Seichan and Vigor.

"Where are we going?" Seichan called down. "We'll be sitting ducks up here!"