DECEMBER 31
Mason, Ramses, and Layne walked single file through a narrow brick aqueduct easily large enough to accommodate a procession of torpedolike, pressurized liquid containers, which could have been unloaded from the flatbeds at any of the remaining functional gatehouses north of the city and shuttled invisibly underground, assuming the Novichok hadn’t already been transferred into smaller containers for ease of dispersion. And that was the problem; they didn’t know what they were looking for any more than they knew where to find it.
Mason explored the tunnel with his flashlight beam, which seemed to dispel little more than the darkness in the immediate vicinity of the lens. He could barely hear a thing over the thunder of his pulse and the splashing of their footsteps in water that smelled like sewage. They had to be underneath Central Park by now, and yet they hadn’t encountered a single surface-access chute or lateral branch.
“Keep your eyes open for trip wires and motion sensors,” he said, his whispered voice echoing from the confines. “Watch for any kind of mechanism that requires movement or force to trigger it.”
Ramses stayed right on his heels to take advantage of the faint glow. While he didn’t have a flashlight, he’d miraculously procured a platinum-plated Sig P226 9mm semiautomatic pistol that shimmered in his grasp. Layne brought up the rear, alternately shining her beam behind them and casting their shadows ahead of them.
“You really think he rigged the tunnel?” Ramses asked.
“I’d be shocked if he didn’t,” Layne said. “If this guy’s as smart as we think he is, he planned for someone to find this aqueduct and set up a way for us to kill ourselves.”
“Wonderful. And here I thought the smell was the best part of this little field trip.”
Mason traced the contours of the tunnel with his light. Sections of the ceiling had crumbled, exposing the rugged bedrock overhead and littering the ground with broken bricks and mortar. Someone had shoved them to the side to clear a path. The air was impossibly still. The sounds of their passage carried hundreds of feet ahead of them into the darkness. Their lights made them easy targets, but turning them off would make them even more vulnerable to whatever trap had been set for them. He brainstormed every possible container or dispersal device that could be used to vaporize chemicals or aerosolize liquids. Watched for any hoses or nozzles or reflections from metal. Listened for the hiss of pressurized gas that would signify it was already too late.
The mud and sediment preserved the smoothed trail of the travoislike contraption the Scarecrow had used to drag his victims into the park, erasing his own footprints in the process. Only smudged and partial impressions of work boots with a deep tread remained.
Mason’s breathing was uncomfortably loud in his own ears. His pulse throbbed at the outer edges of his vision. His nerves were downed power lines. Each step brought him closer to setting off the trap he had yet to identify. There was no doubt in his mind that it was coming. He just prayed they recognized it before it was too—
He stopped mid-stride. There was an astringent smell. Chemicals of some kind.
Layne must have noticed it, too. Her light swept across his back and threw his shadow from one side of the tunnel to the other.
“I don’t like this,” she whispered.
“You were fine with everything up until now?” Ramses said.
“Chemical smells dissipate. This is too strong to have been here for very long.”
She didn’t need to remind them that the lack of circulation meant the source had to be nearby and they still hadn’t seen anything out of the ordinary.
Mason slowly lowered himself to his chest in the shallow water and shone his beam across the surface. No shimmer of fishing line or infrared laser projectors.
Layne traced the arched ceiling with her light. There wasn’t so much as a single cobweb. A section of bricks had fallen, creating a hollow filled with shadows at the farthest reaches of her beam.
Mason stood and shone his light straight down at the water, but he couldn’t see anything through the disturbed sediment. He stepped to either side, straddled the water, and advanced in straight-legged scissor movements to avoid stepping anywhere he couldn’t clearly see the ground.
The smell grew stronger by the second.
“We have to be missing something,” Layne whispered.
Mason paused and studied his surroundings. Slowly. Carefully. No trip wires or pressure plates. No motion detectors or power sources. Nothing but a caustic scent that reminded him of bleach, only not exactly. Like bleach mixed with fuel oil.
“Smells like a pool,” Ramses said.
“Chlorine,” Mason whispered. “Definitely chlorine. But there’s something else. Kerosene? Paint thinner?”
“Where is it?” Layne whispered. A note of panic crept into her voice. “I can’t see a damn thing.”
There was nowhere to hide a bottle or a bucket. No recesses in the walls. Nothing stood apart from the bricks or the darkness, and yet the smell continued to grow stronger.
The right combination of chemicals available in nearly every grocery or hardware store could produce noxious, potentially even toxic gasses from which they wouldn’t be able to escape. Gasses strong enough to overcome them before they reached the nearest surface-access point.
Or worse.
“We’ve got to be right on top of it,” Ramses said.
Mason inched close enough to shine his light into the shadowed recess where the fallen bricks had once been. Judging by the discoloration, the granite had been exposed for decades. Unlike the piles of rubble they’d passed previously, however, this one hadn’t been shoved aside to make way for the transport the Scarecrow had used to move his victims. It sat right in the middle, forcing him to drag the travois out of the water, as evidenced by the sludge smeared up the sloped wall. There was something odd about the arrangement of bricks, too. Almost as though the pile had been deliberately stacked.
“One of us should hang back,” Layne whispered. “Just in case. We can’t afford to risk all of us dying at once.”
Mason stopped and squatted as low as he could possibly go. He shone his light just above the surface of the water, from one side of the tunnel to the other, and noticed two things simultaneously.
A reflection from something buried under the bricks.
And a small black dome protruding from the top of the mound.
“Turn off your light,” he said.
He took a mental snapshot and switched off his flashlight. Turned and snatched Layne’s from her grasp. Extinguished it and prayed it wasn’t already too late.
“Talk to me, Mace,” Ramses said.
Mason closed his eyes, tuned out the metronomic dripping of condensation, and concentrated on the memory of what he’d seen in that fleeting moment before he killed the lights. He described every minuscule detail, as though to grant permanence to the mental photograph that was already starting to fade.
“There’s an ornamental streetlight underneath the bricks,” he said. “Like they have in London, only smaller. Black wrought-iron frame. Glass windows. A single inverted lightbulb with a hole drilled into it, near the fitting, which someone used to fill it with fluid. Two liquids, different densities. The one that settled to the bottom is yellow and oily. The upper is clear but sparkles with what looks like glitter. You can still see it, if you look hard enough. Little glowing dots, suspended in the fluid.”
He remembered from a crash course on chemistry and terrorist applications at the Academy that substances that glowed in the dark contained some amount of phosphorous.
And with that realization, he suddenly understood exactly what the trap had been designed to do.
“The upper fluid is chlorine,” he said. “The particles suspended in it are granules of oxidized phosphorus. The bottom layer is a sulfur-based industrial solvent, like thiodiglycol. Separate, they’re stable, but catalyze the mixture of the three and you’re looking at producing mustard gas. Throw in a large-enough electrical charge and you’d have a miniature napalm bomb that would shower us all with glass and flaming chemicals, even as the gas blisters our skin and shreds our lungs.”
“Did you see the trigger?” Ramses asked.
“Exposed wires pass through the hole in the bulb, into the upper liquid. They’re connected to a motion detector that barely sticks out of the top of the bricks. The domed kind with sensors that cover a full three hundred and sixty degrees. Not a very sensitive model. Battery-powered, little more than a toy. We could work around it in open space, if we could see it.”
“So why can’t we?” Layne asked.
Mason focused on the unmistakable rectangular reflection he’d seen.
“Because the lamp’s been retrofitted with a solar cell. The kind you buy to charge your cell phone and that works even under indoor lighting conditions.”
It was an ingenious trap. The Scarecrow had known that anyone pursuing him down here would have to use either night-vision goggles, which didn’t have sharp enough resolution to discern the motion detector from the bricks until the wearer was well within its range, or flashlights, which would charge the photocells and send a current through the filament in the bulb. Setting off either one would create an electrical charge large enough to ignite the chemical bomb he’d created.
And they’d been shining their lights right at it.
There was no way of knowing how much charge had accumulated in the solar panel, so they couldn’t risk turning on their lights again, even for a second, for fear of reaching the threshold charge and triggering the reaction, which meant they were going to have to beat the motion detector in total darkness.
They could only guess at its range, but even a three-foot radius was more than enough to cover the entire width of the aqueduct. The fact that the Scarecrow had lowered it into the bricks in an effort to conceal it just might work to their advantage, though. By doing so, he’d blocked off everything below the level of the rubble surrounding it.
“We go underneath the detector,” Mason said. “That pile of bricks has to be at least a foot and a half high. We should be able to circumvent it if we keep our bodies pressed to the ground and don’t knock over the lamp.”
“Screw that,” Ramses said.
“Then head back to the house. I won’t hold it against you. We’ve got this from here.”
“You think I’m scared of a little mustard gas and a fiery death? I’m just pissed I have to get down in that water. It smells like whatever died in it shit all over itself in the process.”
Mason smiled in the darkness. There were worse people with whom to share an agonizing death than his old friend.
“I’ll go first,” he said. If he’d misremembered any of the details of what he’d seen, the remainder of their lives could very well be measured in seconds. “Don’t follow too closely, in case something goes wrong.”
“Like ten feet’s going to make a big difference,” Layne said.
Mason lowered himself to his chest and turned his face sideways, both to minimize his profile and to keep his mouth and nose above the vile water. He scooted sideways until he felt his shoulder rise up onto the slope, stretched his arms out in front of him, and planted his palms on the slimy bricks.
Deep breath in.
Long, slow exhalation.
He pushed with his toes, pulled with his hands, and managed to move about four inches.
Again, push with his toes, pull with his hands.
Four more inches.
The glow of the phosphorus faded. He could only guess as to where the lantern was now.
Push with his toes, pull with his hands.
Frigid water sloshed against his cheek, into his ear. The smell was so intense, he could taste it. His shoulders already burned from the exertion. He bumped something hard with his elbow—
A clattering sound, followed by a splash near his head.
He closed his eyes and listened for the electrical sizzle of current passing into the fluid.
Seconds passed.
Nothing.
He exhaled a breath he hadn’t realized he’d been holding and scooted away from the bricks, careful how high he allowed his right shoulder to creep up the sloped wall.
Pushed with his toes, pulled with his hands.
Again and again.
He heard a faint clamoring sound behind him as Ramses knocked the fallen brick back against the pile, but he didn’t even slow.
Push, pull.
“I’m past it,” Layne whispered.
Mason tried to gauge the distance between them. Maybe a dozen feet. The length of his body plus Ramses’. There was no way the sensors reached that far, but he wasn’t taking any chances. Another three feet and he eased to the side to allow Ramses to squeeze in beside him.
“We can’t just crawl forever,” Ramses said. “For all we know, this guy’s standing right above us with night-vision goggles, having a good laugh at our expense.”
“Surely we’re out of range by now,” Mason said. “Layne?”
“Just be ready to run if you’re planning on doing what I think you are.”
He closed the lens of his flashlight inside his fist and switched it on. A pale pinkish glow seeped out from between his fingers. He relaxed them just enough to allow a little more light to leak out, barely enough to see the impression of the pile of bricks behind them, at the farthest reaches of sight. It had to be a good twenty feet away, with the solar cell on the far side, facing the opposite direction.
The tunnel ahead of them was empty, save for the rusted rungs protruding from a flattened section of the wall. He slithered over to them and rolled onto his back. They led upward into a narrow, circular chute. His beam was just strong enough to reveal the hint of the iron disk sealing the top. He waited until Ramses and Layne were nearly on top of him before rising to a crouch.
“Stay here,” he said, and scurried upward, the tapping sounds of his feet striking the sticky rungs echoing below him.
The manhole cover at the top was cold and solid, its edges sharp and uneven where someone had used an acetylene torch to cut through the welding that had once sealed it in place. He braced his feet and shoved the cover upward until he was able to slide it to the side with a screeching sound.
A column of moonlight, barely brighter than the tunnel itself, streaked past him and encircled Layne, who stood at the base of the ladder, silhouetted by the aura of light coming from deeper in the tunnel to her right. She must have given Ramses her flashlight, he realized.
“What do you see?” she whispered.
Juniper shrubs had grown over the manhole. He pushed them aside and found himself looking up into a dense canopy of deciduous trees, their skeletal branches intertwined to such an extent that he could barely see a handful of stars directly overhead. A gentle snow had started to fall, frosting their limbs.
“Nothing.”
Mason transferred his flashlight to his mouth, drew his pistol, and crawled out through the vegetation. The manhole cover beside him was coated with a crust of dirt so thick, it would have been invisible even to someone standing right on top of it, assuming the person dug through the carpet of dead leaves first. A dusting of accumulation concealed a natural trail of stones that almost looked like a staircase ascending the hillside toward the granite formation at the top, above which he could see the outline of the crossbar to which Charles Raymond’s arms had been tied.
The forensic team had packed up and moved on. There was no hint of movement through the surrounding trees, no aura of flashlights in the distance. No voices carried over the distant din of car horns and sirens. There wasn’t a soul within the boundaries of the park.
His phone rang through on his Bluetooth. He tapped the button to connect.
“I’ve picked up your GPS beacon,” Gunnar said, “but it doesn’t appear as though anyone else has.”
“Just poking my head out to get a look around and gather my bearings,” Mason whispered.
“I sent you some more maps that might be of interest. Turns out there are a bunch of subway tunnels in various stages of completion and abandonment down there. And even more proposals that made it to some unknown stage in the drilling process. There’s a lot of drama surrounding the early subway operators, especially during the twenties, with the Independent City-Owned line making an aggressive play to cut the Interborough Rapid Transit Company and Brooklyn Rapid Transit Company out of the East Side and bankrupt them in the process.”
“Now’s not the time for a history lesson, Gunnar.”
“The moral of the story is that the mayor at the time, John Francis Hylan, hated that private interests controlled the subways, so he created his own public line to compete, which required a little creativity and a lot of secrecy. His early proposal for a Second Avenue line incorporated a shortcut under Central Park, some of which we know was actually built because it was incorporated into the Q line.”
“How far is that from my current location?”
“Just under a half mile to the southeast.”
“Guys,” Ramses called from below. “You’ve got to see this.”
“Heading back down,” Mason said.
He slid back into the ground, dragged the manhole cover into place, and descended as fast as he could. The call dissociated into static halfway down. He killed the connection and let go of the rungs as soon as he was within range of the ground. Landed with a splash.
Ramses stood maybe fifty feet ahead of him, framed by mounds of broken bricks and granite. Curtains of roots cascaded from the exposed earth above him. He shone the beam at Layne and Mason as they approached, then to his left, into a gaping maw where the bricks had fallen. They caught up with him and followed the trajectory of the light down into the earth, to the point where it dissolved into the fathomless darkness.
Mason knelt and examined the mess of sludge that had been tracked up onto the rubble. The Scarecrow had definitely dragged Mikkelson’s body through here.
“We’re screwed,” Layne said.
Mason could only nod. He stood, aligned his flashlight beam with the sight line of his pistol, and, without a word, ducked through the hole in the collapsed wall.