"They did," Anakin said, reading from the files. "Different levels of the Zone. The four worker deaths were from overexposure. They were trying to calibrate exact amounts for large crowds. Thousands at once. This factory is definitely Omega's. Zan Arbor can't be far off."

Obi-Wan strode over to read over Anakin's shoulder.

"Zan Arbor had already perfected one-on-one transmission," Obi-Wan said. "But this indicates she's searching for a way to infect a whole city.

" "So we were right," Anakin said. "The proof is in these files."

Obi-Wan pointed to the bottom of the file.

TRACK A EXPERIMENT VOIDED.

TRACK B EXPERIMENT BEGUN.

"Track A and Track B? I wonder what that means," he said.

"This science is over my head," Anakin said, flipping through the holofile. "We'll have to get inspectors in."

"We have enough evidence to go straight to the Supreme Chancellor,"

Obi-Wan said. "That's the only way things get done, these days."

Anakin looked at his chrono. "We have another six minutes before the next droid sweep."

"Let's check out the tunnel."

Quickly they opened the valve and stepped inside the tunnel. They walked down, using their glow rods for illumination. Vents were spaced evenly on the tunnel walls, and the plastoid sides were smooth.

Obi-Wan stepped over to the side and peered into a vent. "I see some ducts and hoses. This must be how the Zone is administered," he said. He stepped away to study a schematic drawing that was light-lasered onto the wall. Tunnels branched out from the main tunnel, and it appeared to be an extensive system.

"The tunnels go on for whole kilometers," Obi-Wan said, surprised.

"Enough to approximate an entire small city, right here in the factory.

This tunnel dips underground and joins the main system. It connects to other smaller tunnels…"

Anakin cocked his head. "Master…"

"It's so detailed. I wonder if it's based on an actual city system….

" "Master." Anakin's voice was urgent now.

Obi-Wan turned. "The droids? I doubt they sweep the tunnels."

"Not droids," Anakin said. "Water."

Obi-Wan whipped around just as a wall of water rushed down the tunnel.

His feet were swept out from under him and he was propelled forward, smashing against the side of the tunnel and then somersaulting out of control against the power of the water. He fought his way to the surface, kicking and stroking. Once his head cleared, he saw Anakin nearby. They were careening down the tunnel with the force of the current.

"Aqua breathers!" Obi-Wan shouted.

He drew his out of his utility belt. Anakin did the same. At least they would not drown. But it would be impossible to fight their way back up the tunnel against the water. On the drawing, the tunnel seemed simply to end in bedrock. They would be smashed against it at this rate.

Then Obi-Wan heard a worse noise, one he hadn't expected. Fighting the pull of the water, he thrashed around until he was facing behind him, the way they had come. At first he could only see the wall of churning water, waves of it coming toward him. Then he realized what was happening.

The tunnel was imploding behind them. In another few seconds, they would be crushed in the collapse.

Anakin saw the danger at the same time as his Master. He did not waste time worrying. His gaze raked the tunnel sides, looking for a way to escape, even as the torrent of water turned him end over end in a tumbling motion that left him dizzy.

Most of the vents were too small, but Anakin remembered something. He had glanced only briefly at the schematic plan, but he remembered a larger vent that came a quarter-kilometer from the end of the tunnel. It had connected to another tunnel that had seemed to come to a dead end. But it would have to do. That would be their only chance to escape the water. That is, if the side tunnels had not been flooded as well.

But how far had they traveled? Which vent was the right one?

Obi-Wan must have had the same thought, but Anakin's Master had studied the blueprint longer. "Anakin!" Obi-Wan shouted over the sound of the rushing water. "Vent coming up on the left, five hundred meters! Grab on!"

"All right!" Anakin yelled, and got a mouthful of water. Choking, he stroked to keep himself above water. He would need every bit of his strength. Dust and debris from the collapsing tunnel now filled the air, making it difficult to breathe. The roar was deafening. Underneath the flow of the water, Anakin felt something else — a deep shuddering, as though the ground itself was moving.

He saw his Master stroke against the water. Anakin fought through the torrent, kicking his legs, and pushing against the water with his arms. He could not make headway.

The Force bounced over the water. It came from his Master. Anakin used it as Obi-Wan intended. He was part of the water now. He could feel the spaces within the drops and was able to let the water break over him and find a way to move against it. He pushed with all his might, but his effort didn't cost him his strength. It doubled it.

He made headway against the water, reaching the side of the tunnel, immediately behind Obi-Wan. Now the trick would be to get inside the vent.

His Master held his cable launcher aloft, over the foaming water, and Anakin saw his objective. He unhooked his launcher as well, keeping himself afloat with one hand as he was knocked against the tunnel wall.

Now the vent was coming toward them — fast, faster than he'd planned for. He saw Obi-Wan's launcher snake out and catch on the vent. Obi-Wan grabbed the cable, fighting his way back against the water. Anakin aimed at the metal grid of the vent and missed.

He called on the Force to help him even as he was swept down past the vent. He pushed against the water, feeling it break against his skin. He felt the spaces between the particles and slipped through them.

Fingers dug into his coveralls and pulled. Obi-Wan reached under his arm and yanked him forward. Anakin was able to grab on to Obi-Wan's cable and hauled himself the rest of the way.

He joined Obi-Wan, hooking his fingers into the grating. The pressure of the water held the vent in place. They pulled with all their strength as the water cascaded over their heads, sometimes submerging them completely.

The tunnel behind them was collapsing, chunks of plastoid and durasteel falling into the churning water and sometimes slamming against them on its way.