“Vincent?” he asked.
Margo turned. D’Agosta was standing behind them in the center of the vault, the air tanks and mask still in a pile by his feet.
“You go on ahead,” he said.
Pendergast looked inquiringly at him.
“Can’t swim,” D’Agosta explained simply.
Margo heard Snow curse fervently under his breath. For a moment, nobody moved. Then Smithback stepped back toward the Lieutenant.
“I’ll help you out,” he said. “You can follow me.”
“I
“Not with all that blubber, you won’t,” Smithback said, snatching a tank off the ground and placing it on D’Agosta’s back. “Just hold on to me. I’ll swim for both of us, if need be. You kept your head above water back in the subbasement, remember? Just do what I do and you’ll be okay.” He thrust a mask into D’Agosta’s hands, then pushed him ahead toward the group.
At the far end of the chamber, an underground river ran off into darkness. Margo watched as first Snow, then Pendergast, adjusted their masks and eased themselves into the dark liquid. Pulling her mask down over her eyes and placing the regulator in her mouth, she slid in after them. The air of the tanks was a welcome relief after the foul atmosphere of the tunnel. Behind her, she could hear a loud splashing as D’Agosta half swam, half floundered through the viscous, lukewarm liquid, Smithback urging him on.
Margo swam as quickly as she could through the tunnel, following the flickering light of Snow’s headlamp, expecting at any moment to feel the massive concussion of the SEAL charges bring the ancient stone ceiling down behind them. Ahead, Pendergast and Snow had stopped, and she pulled up beside them.
“We go down here,” Snow said, popping the regulator from his mouth and pointing downward. “Be careful not to scratch yourself, and for God’s sake don’t swallow anything. There’s an old iron pipe at the base of the tunnel here that leads—”
At that moment they felt, rather than heard, a vibration begin over their heads: a low, rhythmic rumbling that grew to a terrible intensity.
“What’s that?” Smithback gasped, coming up with D’Agosta. “The charges?”
“No,” Pendergast whispered. “Listen: it’s one continuous stream of sound. It must be the dumping of the Reservoir. Prematurely.”
They hung there in the foul liquid, mesmerized despite the danger by the long rolling sound of millions of gallons of water roaring down the ancient network of pipes that crossed and recrossed above their heads, heading directly for them.
“Thirty seconds until the rest of the charges go,” Pendergast said quietly, checking his watch.
Margo waited, trying to steady her breathing. She knew that if the charges failed, they’d be dead within minutes.
The tunnel began to vibrate violently, the surface of the water jiggling and dancing. Small pieces of masonry and cement began to rain down into the water around them. Snow tightened his mask and took a last look around, then sank beneath the surface. Smithback followed, pushing the protesting D’Agosta before him. Pendergast motioned Margo to go next. She sank into the darkness, trying to follow the faint light of Snow’s headlamp as it descended into a narrow, rust-coated pipe. She could see the ungainly thrashing of D’Agosta subside into more regular movements as he became used to breathing tank air.
The tunnel leveled out, then snaked around two bends. Margo took a quick look behind to reassure herself that Pendergast was following. In the dim light of the swirling orange effluent, she could see the FBI agent motion her forward.
Now, she could see the group pausing at a junction ahead of her. The ancient iron pipe ended and a gleaming steel tube continued onward. Beneath her feet, at the point where the two tunnels met, Margo could see a narrow tube leading downward. Snow gestured ahead, then pointed upward with his finger, indicating that the vent riser to the West Side Lateral was directly ahead.
Suddenly, there was a roar from behind them: an ominous, deep rolling sound, horribly magnified in the tight water-filled space. Then a sharp concussion sounded, and another, following one upon the other in rapid succession. Beneath the wildly flickering beam of his headlamp, Margo could see Snow’s eyes widen. The final set of charges had gone off barely in time, crushing the spillways from the Devil’s Attic, sealing it forever.
As Snow frantically signaled them toward the riser, Margo felt a sudden tug at her legs, as if a tidal undertow were pulling her back toward the rally point. The feeling stopped as quickly as it had begun, and the water around her seemed to grow strangely dense. For a split second she had the strange sensation of hanging motionless, suspended in the eye of a hurricane.
Then an enormous blast of overpressure boiled up from the iron pipe behind them, a roiling cyclone of muddy water that caused the tunnel itself to jerk and dance spasmodically. Margo felt herself battered against its iron flanks. Her mouthpiece came loose and she reached for it frantically, hands grabbing through the storm of bubbles and thrashing sediment that surrounded her. There was another burst of pressure and she felt herself forced downward, sucked into the pipe beneath her feet. She righted herself desperately and fought to swim back up to the junction, but a horrible suction only pulled her deeper into unguessable depths. The roaring sound continued like the rushing of blood in her ears. She felt herself being knocked from side to side against the walls of the pipe, a piece of flotsam in the flood. Far above her head now she could see, through the dim illumination of Snow’s headlamp, Pendergast staring at her, his hand reaching down, tiny as a doll’s, from what seemed countless miles away. Then there was another blast, the narrow tunnel collapsed above her head with a shriek of protesting metal, and as the endless rumbling continued, she felt herself falling ever farther into a watery darkness.
HAYWARD JOGGED UP the Mall toward the Bandshell and Cherry Hill, Officer Carlin by her
