Coral explained, “Have you ever seen an overloaded transformer blow? It can take out an entire power pole. Now picture one the size of this cavern. One with a concentrated antimatter core. It has the capability of taking out the entire Arabian Peninsula.” The sobering thought silenced them all.

Safia watched the vortex of energies churn. The funnel in the center continued to drop, slowly, inexorably. Primitive fear laced through her.

“So what can we do?” This question came from an unlikely source. Cassandra. She pulled up her night-vision goggles. “We have to stop this.” Omaha scoffed. “Like you want to help?”

“I don’t want to die. I’m not insane.”

“Just evil,” Omaha muttered.

“I prefer the word ‘opportunistic.’ ” She directed her attention back to Coral. “Well?”

Coral shook her head.

“We ground it,” Painter said. “If this glass bubble is the insulator for this energy, then we need to find a way to shatter the bubble’s underside, ground the electrical storm, send its energy into the earth.” “It’s not a bad theory, Commander,” Coral said. “Especially if you could break the glass under the lake itself, get the antimatter waters to drain into the original Earth-generated water system from whence it came. Not only would the energy dissipate, but it would lessen the risk of an antimatter chain reaction. The enriched waters would simply dilute away to the point of impotency.” Safia felt a glimmer of hope. It didn’t last past Coral’s next words.

“It’s the practical application of that plan that’s the big problem. We don’t have a bomb massive enough to blow out the bottom of the lake.” For the next few minutes, Safia listened to the discussions of possible explosive devices while knowing what lay implanted in her own neck, knowing what had happened back in Tel Aviv, back at the British Museum. Bombs marked the turning points in her life. They might as well mark her end. The threat should have terrified her, but she was beyond fear.

She closed her eyes.

She half noted the various ideas being bandied aloud, from rocket-propelled grenades even to the bit of C4 in her neck.

“There’s nothing here strong enough,” Coral said.

“Yes, there is,” Safia said, opening her eyes. She remembered the blast at the British Museum. She pointed down into the courtyard. “It’s not a camel, but it may do.” The others stared where she pointed.

To the giant iron sphere resting in the glass palm.

“We sink it into the lake,” Safia said.

“The world’s largest depth charge,” Danny said.

“But how do you know it will explode like the camel?” Coral asked. “It might just fizzle like the iron maiden. These iron artifacts don’t all function the same way.” “I’ll show you,” Safia said.

She turned and led the way back down the stairs. Once in the main room, she waved to each of the sand-painted walls. “Opposite the entry is the first Ubar, a rendering of its discovery. Over on that far wall is the depiction of Ubar above. Its face to the world. And this wall, of course, is the true heart of Ubar, its pillared glass city.” She touched the painting of the palace. “The detail is amazing, even down to the sandstone statues guarding the entrance. But on this picture both statues are shown.”

“Because one was used as a vessel for the first key,” Omaha said.

Safia nodded. “This depiction was done obviously before the destruction. But note what’s missing. No iron sphere. No glass palm. In the center of the painting’s courtyard stands the queen of Ubar. A place of prominence and importance. X marks the spot, so to speak.” “What do you mean?” Cassandra asked.

Safia had to bite back a sneer. Her effort to save her friends, to save Arabia, would also be saving Cassandra. Safia continued, not meeting the woman’s eye. “Symmetry was important in the past. Balance in all things. The new object was placed on a site that matches the position of the queen in the rendering. A place of distinction. It must be important.” Omaha turned, staring out the entry to the iron sphere. “Even the way the palm is positioned. If you straightened the wrist, it would be like she’s throwing the sphere toward the lake.” Safia faced them all. “It’s the queen’s last key. A failsafe. A bomb left to destroy the lake if needed.” “But can you be sure?” Painter asked.

“What does it hurt to try?” Omaha countered. “Either it works or it doesn’t.”

Coral had wandered to the entrance. “If we’re going to try this, we’d better hurry.” Safia and the others crowded forward.

In the center of the cavern, a glowing funnel cloud twisted and writhed.

Below it, the antimatter lake had begun to churn, matching the vortex on the roof.

“What do we do first?” Painter asked.

“I have to place my hands on the sphere,” Safia said. “Activate it like all the other keys.” “Then we get the ball rolling,” Omaha said.

7:35 P.M.

O MAHA STOOD on the sandy path out in the courtyard. It had taken a minute to sweep the trail so it reached the cradled sphere. Safia stood before the four-foot-wide globe of red iron.

The skies raged above.

Safia approached the sphere. She rubbed her palms, then reached between the glass fingers of the sculpture.

Omaha saw her shoulder flinch, the bullet wound paining her. He wanted to rush to her side, pull her away, but she bit her lower lip and placed both palms on the sphere.

As her skin touched metal, a crackling blue flash arced over the iron’s surface. Safia flew back with a yelp.

Omaha caught her in his arms and helped her gain her feet on the sand.

“Thanks.”

“Sure, babe.” He kept one arm around her and helped her back to the palace. She leaned on him. It felt good.

“The grenade is set on a two-minute timer,” Painter said. “Get to cover.” He had planted the explosive charge at the base of the sculpture. The plan was to blast the sphere free.

Gravity would do the rest. The avenue beyond the palace flowed all the way to the lake. Purposeful, Safia had said. The ball, once freed, was meant to roll to the lake on its own.

Omaha helped Safia back into the main room.

A blindingly bright flash flared behind them, burning their shadows on the far wall of the main room. Omaha gasped, fearing it was the grenade.

He jerked Safia to the side, but there was no explosion.

“One of the static bolts,” Coral said, rubbing her eyes. “It struck the sphere.”

Safia and Omaha swung around. Out in the courtyard, the iron’s surface shimmered with blue energies. They watched the glass sculpture melt slowly, tilting on its own. The hand spilled the ball onto the courtyard floor. It bobbled, then rolled toward the arched entry.

It passed through and continued on.

Coral sighed. “Beautiful.” Omaha had never heard so much respect uttered in one word.

He nodded. “That queen would have made a great professional bowler.”

“Down!” Painter shoved them all to the side, clotheslining Omaha across the neck.

The explosion deafened. Glass shards spattered into the room from the courtyard outside. Painter’s grenade had gone off on schedule.

As the blast echoed away, Omaha met his eyes. “Good job there.” He patted Painter on the shoulder. “Good job.” “It’s still rolling!” Danny called from above.

They all hurried up the stairs to the upper balcony, where everyone else was gathered.

Omaha pushed forward with Safia.

The course of the iron sphere was easy to follow. Its movement drew bolts from the roof, zapping it again and again. Its surface glowed with a cerulean aura. It bounced, rolled, and wended its way down the royal avenue.

Forked lightning struck and dazzled—but it kept rolling to the lake.

“It’s energizing itself,” Coral said. “Drawing power into it.”

“Becoming the depth charge,” Danny said.

“What if it blows up as soon as it touches the lake?” Clay asked, hanging back, ready to duck into the palace at the first sign of trouble.

Coral shook her head. “As long as it keeps dropping, moving through the water, it’ll only leave a trail of annihilation. But the reaction will end as soon as the ball moves on.” “But when it stops, rests at the bottom…” Danny said.

Coral finished: “Then the weight of all the water above it, pressing on the stationary object, will trigger a localized chain reaction. Enough to light the proverbial fuse on our depth charge.” “Then boom,” Danny said.

“Boom indeed,” Coral concurred.

All eyes remained on the glowing ball.

All eyes saw it reach the halfway point, roll along a ramp, hit a tumbled pile of debris from Cassandra’s bombardment…and stop.

“Shit,” Danny mumbled.

“Shit indeed,” Coral concurred.

7:43 P.M.

S AFIA STOOD with the others on the balcony, as dismayed as the rest. Arguments raged around her.

“What about using one of the RPGs?” Cassandra asked, staring through her night-vision goggles.

“Shoot a grenade at an energized antimatter bomb?” Omaha said. “Yeah, let’s do that.” “And if you miss the debris pile,” Painter said, “you’ll bring down another wall and block the road even more. Right now, it’s only hung up. If it could be rolled aside a couple of feet…” Cassandra sighed. Safia noted the woman’s finger still pressed the transmitter, protecting it from anyone’s reach. Cassandra could definitely focus. With all that was going on, all the danger, she was not letting go of her trump card, keeping it in play, clearly intending to use it if everything worked out. She was a stubborn fighter.

Then again, so was Safia.

Clay held his arms crossed over his chest. “What we need is someone to go out and give it a good push.” “Feel free to try,” Cassandra said with clear disdain. “The first sign of movement and you’ll be bathing in molten glass.” Coral stirred, previously lost in deep thought. “Of course. It’s movement that draws the bolts, like the rolling ball.” “Or my men,” Cassandra added.