“There you go,” Horlocker said into the speakerphone. “We could seal it off and proceed from there. Right?”

There was a pause. “I suppose so, sir.”

“So we could trap them.”

“Maybe.” Masters sounded dubious even through the speakerphone. “But what then? We couldn’t lay siege. And we couldn’t very well go in and root them out. It would be a stalemate. We need more time to grid the route.”

Margo glanced at D’Agosta, looking on disgustedly. It was what he’d been recommending from the beginning.

Horlocker pounded on the table. “Goddammit, we don’t have time! I’ve got the governor and the mayor breathing down my neck. They’ve authorized me to take any action necessary to stop these killings. And I plan to do just that.”

Now that Horlocker had made up his mind, his determination, his impatience, was remarkable. Margo wondered just what it was the mayor had said in their telephone conversation that had so put the fear of God into the Police Chief.

Hausmann, the engineer, removed his pen from his mouth long enough to speak. “How can we be sure these creatures live in the Astor Tunnels, anyway? I mean, underground Manhattan’s a large place.”

Horlocker turned toward Margo. She cleared her throat, aware of being put on the spot.

“From what I understand,” she said, “there are a lot of underground homeless throughout the tunnels. If there were a concentration of these creatures elsewhere, the homeless would know about it. Like we said earlier, there’s no reason to doubt the word of this Mephisto. Besides, if the creatures have any of the characteristics of the Mbwun beast, they’ll shun light. The deeper their nest, the better. Of course,” she added quickly, “Pendergast’s report will—”

“Thank you,” Horlocker said, stepping hard on her final words. “Okay, Masters? You’ve got the brief.”

The door swung open suddenly, the squeaking of rubber wheels announcing Frock’s return. Margo looked up slowly, almost afraid to see the expression on the old scientist’s face.

“I think I owe everyone here an apology,” he said simply, wheeling up to the table. “As I went through the Museum’s halls just now, I did my best to look at things objectively. And on reflection, I’m afraid I may well have been wrong. It’s difficult to admit it, even to myself. But I suppose the theory advanced by Margo best fits the facts.” He turned toward Margo. “Please forgive me, my dear. I’m a tiresome old man, overly fond of his pet theories. Especially when it comes to evolution.” He smiled wanly.

“How noble,” Horlocker said. “But leave the soul-searching for later.”

“We need better maps,” the voice of Masters continued, “and more information about the hostiles’ habits.”

“Damn it!” Horlocker cried. “Aren’t you hearing me? We don’t have time for a geological survey here! Waxie, what’s your take on this?”

There was a silence.

Frock eyed Waxie, who was staring out the window as if hoping to see the much-needed answer spray painted across Central Park’s Great Lawn. The Captain frowned, but no words came.

“The first two victims,” Frock said, still eyeing Waxie, “appear to have been washed out in a storm.”

“So they were nice and clean when we found them,” Horlocker growled. “Good. So what?”

“The gnaw marks on these victims don’t show signs of hurried work,” Frock continued. “It would appear the creatures had plenty of time to do their work unmolested. That would imply the bodies were near, or perhaps in, their lair at the time the marks were made. There are numerous analogs in nature.”

“Yeah?”

“If a few victims can be flooded out by a storm, what would it take to flood the lair itself?”

“That’s it!” Waxie cried, turning from the window in triumph. “We’ll drown the bastards!”

“That’s crazy,” said D’Agosta.

“No, it isn’t,” Waxie said, pointing excitedly out the window. “The Reservoir’s got to drain out through the storm system, right? And when the storm drains get overloaded, doesn’t the overflow go into the Astor Tunnels? Wasn’t that why you said they were abandoned?”

There was a short silence. Horlocker turned toward the engineer with a quizzical look, who nodded. “It’s true. The Reservoir can be dumped directly into the storm drain and sewage system.”

“Is it feasible?” Horlocker asked.

Hausmann thought a moment. “I’ll have to check with Duffy to be sure. But there are upward of two thousand acre feet of water in the reservoir, at least. That’s ninety million cubic feet. If even a fraction of that water—say, thirty percent—were suddenly released into the sewer system, it would completely overwhelm it. And as I understand it, the overflow would go into the Astor Tunnels, then on into the Hudson.”

Waxie nodded triumphantly. “Exactly!”

“Seems like a pretty drastic step to me,” D’Agosta said.

“Drastic?” Horlocker repeated. “Excuse me, Lieutenant, but we just had the better part of a subway train massacred last night. These things are out for blood, and it’s getting worse, fast. Maybe you’d prefer to walk up and give them a summons, or something. But that just won’t do the trick. I’ve got most of Albany on my back, demanding action. This way”—he waved his hand in the direction of the window and the Reservoir beyond—“we can get them where they live.”

“But how do we know exactly where all this water’s going to go?” D’Agosta asked.

Hausmann turned to D’Agosta. “We have a pretty good idea. The way the Bottleneck works, the flow will be confined to the very lowest level of the Central Park quadrant. The overflow shunts will direct the water straight down through the Bottleneck into the deepest storm drains and the Astor Tunnels, which in turn drain into the West Side Laterals and finally into the Hudson.”

“Pendergast did say that the tunnels south and north of the Park had been sealed off years before,” D’Agosta said, almost as if to himself.

Horlocker looked around, a smile creasing his features. To Margo, it looked awkward, as if Horlocker didn’t use those particular muscles very often. “They’ll be trapped beneath this Bottleneck, swept away and drowned. Objections, anybody?”

“You’d have to make sure all the creatures were down there when you let the Reservoir go,” said Margo.

Horlocker’s smile faded. “Shit. And how the hell can we do that?”

D’Agosta shrugged. “One of the patterns we found was that no killings occurred during a full moon.”

“That makes sense,” Margo replied. “If these creatures are like Mbwun, they hate light. They probably remain below during the full moon.”

“What about all the homeless living down there, under the Park?” D’Agosta asked.

Horlocker snorted. “Didn’t you hear Hausmann? The water will go straight to the lowest levels beneath the city. We’ve heard the homeless shun that area. Besides, the Wrinklers would have killed any that wandered too deep.”

Hausmann nodded. “We’ll plan a limited operation that wouldn’t flood anything but the Astor Tunnels.”

“And any moles that might be camping out in the path of the descending water?” D’Agosta persisted.

Horlocker sighed. “Ah, shit. To be on the safe side, I guess we’d better roust them out of the Central Park quadrant and put them in shelters.” He straightened. “In fact, we could kill two birds with one stone—and maybe even get that Wisher woman off our backs, to boot.” He turned to Waxie. “Now this is what I call a plan,” he said. “Nicely done.”

Waxie blushed and nodded.

“It’s a hell of a big place down there,” D’Agosta said, “and those homeless people aren’t going to go willingly.”

“D’Agosta?” Horlocker snapped. “I don’t want to hear you whining any more about why it can’t be done. For Chrissakes, how many homeless are we talking about below Central Park? A hundred?”

“There’s a lot more than—”

“If you’ve got a better idea,” Horlocker interrupted, “let’s hear it. Otherwise, stow it.” He turned to Waxie. “Tonight’s the full moon. We can’t afford to wait another month: we’ll have to do it now.” He leaned toward the speakerphone. “Masters, I want all underground spaces in the vicinity of Central Park cleared of homeless before midnight. Every damn tunnel, from Fifty-ninth Street to One Hundred-tenth, and from Central Park West to Fifth Avenue. A night in the shelters will do the moles good. Get the Port Authority, the MTA, anyone you need. And get me the Mayor, I’ll need to brief him on our plan of action, get the rubber stamp.”