Chappalar moved ahead of me, holding his arms crossed against his chest so his gliders were folded tight to his body. The walkway forward was camel-eye narrow; if he hadn’t trimmed his sails, they would have brushed against lockers on both sides, knocking off all the hung decorations. I followed, tucking my arms in too — I didn’t have Chappalar’s wingspan, but how often do I have to use the word "Amazonian" before you figure out I’m a big old girl?

Probably three times less than I’ve used it already. Redundancy, thy name is Faye.

Beyond the lockers lurked the vat room: a chamber the size of a skating rink, dominated by massive metal tanks. Water from the local aquifer got pumped up from below, fed through a line of processing vats and squirted out the other end, purified of toxic metals and native Demoth microbes. This station was supposed to have three working lines of four vats each; but the two oldest lines had been jinxed with mechanical gremlins over the past year, forcing the staff to hammer away at stubborn pumps, jammed stir-paddles, and hiccuppy valves. Scarcely a week passed that one line didn’t conk out for a day or so… and over last Diaspora weekend, both bad lines went tits up together.

No wonder city council wanted to rip out the old and put in state-of-the-art replacements. The only question was why they’d let the place degrade so badly to begin with. Elizabeth Tupper, plant manager, must have really cranked someone off.

The moment Chappalar and I entered, we could tell which two lines were on the futz: the ones that were half-dismantled, their high-up access panels open to expose wiring and plastic tubes. A pair of wheelstand stairways had been rolled up to the guts of the nearest vat, as if two workers had been poking around side by side, consulting with each other on how to get a bit more service out of the heap of junk… but no one was there now. No one anywhere in sight.

I turned to Chappalar. "They’re all on rest break?"

He shrugged. "Could be a staff meeting."

"The regular staff meeting is tomorrow." Chappalar would have known the schedule if he’d done his homework on the plant… but then, he’d been busy playing lose the spoon with Maya, hadn’t he? Anyway, this scrutiny had got docketed under my name, so I was the one supposed to know the facts. In his way, Chappalar was giving me a vote of confidence — trust I would cover the background trivia so he wouldn’t have to.

"Even if it’s not time for the regular meeting," Chappalar said, "Ms. Tupper might have called an impromptu one. Perhaps she assembled the crew so she could distribute a memo on putting away one’s tools." He rolled his eyes. I was beginning to get a picture of Ms. Memo-Making Tupper. "Or," Chappalar went on, "they may have received a delivery of spare parts at the other door, and everyone’s helping unload."

Possible. Plausible. Considering the rat’s banquet of pipe and cable strewn round the floor, they must send out for spare parts frequently. Still… the place seemed needle-nick quiet. And abandoned. I was getting a case of the hinkies, some of that "human intuition" Chappalar grumbled about.

"Let’s keep on our toes," I told him, keeping my voice low. "This is making me edgy."

He gave me a look — a studiedly neutral look reserved for first-time proctors who talk like escapees from a melodrama. Then again, his inner ear-sheaths lowered a fraction, letting him listen better for suspicious sounds. He was giving me the benefit of the doubt, even if he thought I was overreacting.

Warily, I moved forward. Chappalar followed. As we drew level with the stairways up to the vat controls, I yielded to impulse and climbed the steps — up two full stories above the ground till I was face-to-face with a jumble of fiber optics and plumbing.

Chappalar flapped up beside me and landed lightly on the other set of stairs. His head suddenly jerked; he put a hand to his cheek. "Wet." He looked down and pointed to a black poly pipe just below eye level; it had a pinhole in it, shooting up a thin spray of water that had hit him in the face.

"That can’t be good," I said.

"Not unless you’re in need of a shower." He ducked around the spray and leaned forward to peer at the pipe. "There’s more corrosion here than just that pinhole. Look at this wire. See where the insulation is missing?"

I leaned in beside him. Yes: specks of damage on several wires, on the pipe, and on the readout of a nearby pressure monitor. I could pick up something else too — a sharp scent that curled my nose hairs.

"Acid," I whispered.

"What do you mean?"

"I can smell it."

"Oh." Ooloms flip-flop in their respect for the Homo sap nose. Sometimes they act as if they don’t believe in smell at all, as if we’re shamming our ability to use a sense they don’t have. Other times they treat us with something close to awe: astounding creatures that we are, privy to profound sensations that are hidden from their race.

This time, Chappalar decided to be impressed. "What type of acid is it?" he asked.

"Don’t know." I could have downloaded the world-soul’s library of smells, to compare this pickly odor to the ones on file; but what would be the point? Showing off to Chappalar? And did I want to fill my brain with a catalogue of bitter stinks?

Our cowardly Faye, rationalizing. To avoid taking another kick at the data-tumor can.

"Who cares what acid it is?" I said briskly. "The question is where it came from."

Chappalar looked disappointed at the fickleness of my nose; but he turned back to the innards of the control panel. "I can’t imagine why anything here would leak acid. Pumping and filtration equipment shouldn’t use strong chemicals. I suppose there might be batteries, for backup power supply if the main current goes out…"

He scanned the pipes upward, searching for a source of the spill. I didn’t. I’d memorized schematics of all the equipment in the plant; nothing used so much as a dribble of high-corrosive.

"This is all wrong," I muttered. "I’m going to call Protection Central."

"Faye." You didn’t need sensitive Oolom ears to hear the reproof in Chappalar’s voice. "This is your first scrutiny," he said, "and you’re ready to see everything as suspicious. I was the same when I started. But think — this is just a water-treatment plant, in a quiet city on a quiet planet. Nothing sinister goes on here.

My guess is the workers were just cleaning out pipes with an acid wash. They spilled some, everyone rushed to the first-aid station or the shower, and…"

His ear-lids suddenly opened wider.

"What?" I whispered. A moment later I heard the sound too: footsteps tapping toward us from the far end of the room.

Chappalar gave me a gentle smile, with only a hint of I-told-you-so. "Hello!" he called. "We’re from the Vigil."

The footsteps sped up. In a moment, two figures hove into view at the bottom of the stairs below us — a man and a woman, both human, wearing the standard gray overalls of city maintenance staff. They looked mainstreet-ordinary: in their thirties, one Asian, one Cauc, both with shoulder-length black hair.

Just one problem: I’d gone through the files on everyone who worked here. The files included ID photos; and these two people weren’t in the pictures.

"Good morning," Chappalar was saying. "We’ve come to look around…"

He began to lift his arms as if he intended to launch off the stairs and glide down to the newcomers. Bolt-fast I grabbed him, pulling him back. He gave me a wounded look. "Please, Faye; this kind of behavior…"

That’s when the folks on the ground drew their pistols.

I only had an instant to recognize the weapons: jelly guns, able to shoot a blob of sticky goo up to forty meters where it would splatter on impact. Police loaded them with clots of neural-scrambling syrup — even if the shot didn’t hit you dead on, one tiny splash touching bare skin would send frazzled messages to your brain, interfering with most motor functions. Petit mal on a plate.