“It is.” Kirsten glances up from the screen of her laptop. “Nine stories, only one above ground.”

“There’s a culvert down there by the creek a little to the south that can’t go anywhere but into the building. Unless you have a better suggestion?”

Kirsten shakes her head. “There’s only two doors on the top floor. One’s the main entrance. The other’s Petie’s concession to the fire regs. It may not even be functional.”

“Looks like the pipe’s it, then. Any idea where that’ll take us?”

“Probably into the air-conditioning system. Sewers wouldn’t empty out into the stream like that.”

Koda draws a deep breath, lowering the binoculars and turning to look at her lover. From somewhere comes a line of remembered poetry. Mine eyes desire thee above all things.

For a long moment, she drinks in the sight of Kirsten, pale hair touched to silver by the waning light, lithe body half-stretched out on the grass, her eyes in shadow. “It’s time,” she says softly. “We’d better start moving.”

For answer Kirsten only nods, folding down the screen of her computer and tucking it into her pack. Asi stretches and gets to his feet, looking expectantly from Kirsten to Koda.

“No, boy. You can’t go with us.” Kirsten slips her arms around him, holding him for a long moment with her face pressed into his shoulder. When her hands come away, his collar comes with them. She lays it in the grass beside him, getting to her feet reluctantly, as if every joint in her body aches. “Down, boy,” she says quietly, and he subsides into the grass. “Stay.” She turns away and begins the descent, not looking back.

Koda lays her hand briefly on the big dog’s head, ruffling his mane behind his ears. “Be free,” she says, and follows Kirsten down the hillside.

*

A trickle of water still runs from the culvert, clear in the narrow beam of Koda’s penlight. The pipe itself measures perhaps a yard across, a black maw opening into the side of the hill. It smells sharply of coolant, with an underlying hint of ammonia. She plays the light about the upper curve, where the broken remains of mud-plaster nests cluster together, some retaining their narrow-necked jar shape, others mere circles of dried earth. “Cave swallows,” Koda says quietly. “Gone south.”

“Left the poop behind,” Kirsten observes.

“Oh, yeah. Nobody said this was gonna be a clean job. We’re going to have to do this on hands and knees.” From her pack, Koda pulls a pair of leather gloves and a bandana, which she ties loosely around her neck.

“Try not to get them wet,” Kirsten says, likewise smoothing gloves over her own hands. “The place will be cold—really cold. The droids’ circuits can take normal heat, but a lot of the manufacturing equipment is temperature-sensitive.”

Koda shifts the rifle across her back, checks her belt one last time for the extra magazines and the half-dozen grenades she has hoarded all the way from Ellsworth. A pouch holds a small lump of C-4 and a detonator, quietly liberated from the armory at Pyramid Lake. They could simply have asked for it, of course, but Dakota and Annie Rivers off in search of Annie’s parents on the Mendo Coast could have no legitimate use for plastique. Lastly, she works the penlight into the band of her hat, pointing straight up, and pulls the bandana up over the lower part of her face. “Ready?”

“Let’s do it.”

Ducking beneath the curve of the pipe, Koda drops to hands and knees and begins to crawl forward. The miniature flash shows her the walls rising to either side, the thin runnel of mud-and-guano thickened water down the bottom. By splaying her hands and knees, she finds that she can keep mostly out of the wet. The lime-covered surface to either side crunches faintly as she moves, Kirsten following in her tracks. It occurs to Koda that if there are noise or motion sensors in the conduit their mission could be cut short before they even get near their objective. But prints like miniature human feet and the rippling sign of a snake’s passage seems to indicate that the local wildlife comes and goes unmolested; the heavy stuff will be up ahead.

The first hint of it has nothing to do with Westerhaus’ security system. From up ahead comes a whiff of rancidly acidic stench. No surprise there; the prints, after all, were fair warning. She pauses to tighten her bandana over her nose and mouth, even as her eyes begin to water. “Okay,” she says. ” We got chemical warfare here. We try to get through this next bit as fast as we can. Don’t breathe if you don’t have to.”

Kirsten’s answer is a wry snort. “What is it? Eau de skunk?”

“You got it. Recent, too.”

The stink grows rapidly from worse to overwhelming as they advance down the tunnel. Koda rises to a crouch, getting her feet under her, and shambles down the conduit at a gait that is half frog-march, half bear-dance. If skunks have the run of the place, she and Kirsten are unlikely to trip alarms—unless, of course, the skunk is up ahead somewhere, in which case matters may become radically worse. The stinging in her eyes almost blinds her to the single bright spot of the penlight as it picks out the dark curve of an intersecting pipe. “Turn,” she says, half-gagging. “This one should head us up toward the building.”

“Oh, gods,” Kirsten moans behind her. “I hope the skunk hasn’t been there, too.”

It has not. The stench dissipates within a few yards, and Koda drops gratefully back to hands and knees, pushing the bandana away from her face. They are too far up the pipe for the swallows. Here there is only the thin stream of water, icy cold now closer to the Institute, and a faint odor of mold. She can hear Kirsten taking in the chill air in gasps.

By Koda’s reckoning they have gone perhaps another fifty yards when the flash picks out the shape of an obstruction ahead. Slipping the light from her hatband, she plays it over a steel grate that blocks the tunnel. It, or something like it, had to be here; otherwise the local wildlife would have free access to the Institute’s climate control in particular and the building in general. A quick run of the flash over the rim shows it is neither bolted nor welded into place. “What d’you think? Go for the hinges or the lock?”

“Hinges,” Kirsten says without hesitation. “Maybe we can get the pins out. Otherwise we’ll have to blow the thing.”

Koda nods agreement. She does not want to have to set off a grenade or the plastique in a confined space. Still less does she want to alert the droids inside the facility by noise or vibration. “Hinges it is,” she says.

The openings in the barrier are just large enough that Koda can pass a hand through. With the penlight, she locates the pins to one side. Reaching for her knife to try to prize them up, she leans against the grate and nearly loses her balance as it swings under her weight. “What—” She scrambles away from it. “You woudn’t happen to know if Westerhaus booby-trapped things like this, would you?”

“Not as far as I know,” Kirsten answers. “But then, I wouldn’t know.”

When nothing happens, Koda gives the grate a careful push. It swings soundlessly open. Ahead, the light shows only more tunnel; no wires, no suspicious projections on the walls of the passage, no obvious sensors, no skunks. “Okay,” she says. “Let’s move.”

After ten yards or so, the tunnel begins to angle sharply upward, the first sign that they may be nearing the building. Faintly, from somewhere above comes the hum and clatter of machinery. Going by Kirsten’s copy of the blueprints, Koda knows that the physical plant is on the lowest level: air conditioning and heating machinery, generators, independent water supply. The plans show various possibilities from that point. Depending on the security measures, they can go strolling down the corridors—unlikely—or take to the ducts and vents that honeycomb the place and hope they are not furnished with deadfalls, electrified, or otherwise inhospitable.

As the slope levels out again, the tunnel broadens, finally opening out into a rectangular vestibule with a vaulted roof. A channel in the floor carries the runoff from the machinery into the tunnel, passing under a steel door. From the other side, the cacophony of the gears and flywheels and fans is deafening, echoing off the walls of the passage and reverberating in the metal of the door. Kirsten, beside her, mimes pushing at the door, then shrugs. It seems unlikely that the same luck will strike twice, but Koda gives a shrug back in answer. It is worth the try. She puts her shoulder to the steel and pushes.

Nothing. She pushes a second time.

Still nothing. She tries the handle. The door is locked.

With Kirsten holding the light, Koda fixes a small charge of C-4 on the lock plate and wires up the detonator. She motions Kirsten back beyond the expansion of the tunnel, then steps back and flings herself flat on the wet floor beside the other woman. Triggered remotely, the explosive goes off with a muffled whump! and a shower of sparks.

A moment later, the door swings open to her touch, and the roar of the machinery spills through like the thunder of a great waterfall, a physical pressure not just against her eardrums but a force pressing against her whole body, rattling her bones. She lets it wash over her, through her, not resisting, like a spirit passing through her in ceremony. Take it in. Direct it. Master it. Beside her, Kirsten presses both hands to her temples, damping down her implants. For her, with every vibration magnified, the blast of sound must be infinitely worse. “Are you all right?” Koda mouths.

She receives a nod in reply and a reassuring hand on her arm, and steps into the maelstrom that fills the entire level of the building. Next to the door stands the HVAC equipment, the drainage conduit filled with viscous dark water. The open pipe leads out beneath a cage of bars plastered with warning signs: HIGH VOLTAGE. AUTHORIZED PERSONNEL ONLY. SAFETY EQUIMPMENT MANDATORY. Beyond them looms the huge bulk of the condenser, an Army-green block the size of a small bungalow, its sides and top studded with dozens of meter-wide fans whirring at different speeds, in opposite directions. The smell of overheating wire comes off it, together with a blast of heat. Beyond the bars the air ripples with shimmer, the kind that rises off the blacktop under the July sun. To one side Koda can see the labyrinth of its condenser coils, twined and turning back on themselves like the intestines of some great beast. The roar of its motors echoes off the high ceiling, the concrete walls. Koda takes an involuntary step back, then checks herself abruptly. Get a grip Rivers. You’re not St. George. This ain’t no dragon, just an overgrown window unit. Her gut does not quite believe her, though, and she remains where she stands, studying the huge machine. Cutting off the ventilation might bring someone down to repair it, someone who could be used as guide or hostage or source of information. But the task is impossible. Tacoma might know how to slay this monster, but she has not the electrical or specific mechanical skills to know where to attack it effectively. She doubts there is a circuit breaker box where she can simply turn it off. On the other hand, I could short out the entire building, possibly destroying Westerhaus’ little project, while electrocuting myself. . .. The cost-benefit ratio does not compute.