I walked back to the boards. I stood in front of the exposed segment of the wall that the dry-erase boards had covered before I'd rotated them away. I waved my hand again.

"The breeze is coming from here."

Maggie rolled her eyes. "I'm not even going to-"

I stuck my hand through the wall. Maggie yelped. I pulled my hand back. "Tingles."

She came over to me. "Holy shit." She touched it and her finger and the wall rippled slightly. "It's a hologram."

"Can you short it out?"

She gave me a dubious look, but reached out again. Energy pulsed down her arm. A two-meter section of the wall disappeared. In its place was a standard air duct.

"There's your air source," said Maggie, amused.

I examined the grill. It looked ordinary enough. "A hologram of a wall over an air duct?" I said. "What the hell for?"

I grabbed the edges of the grill. It groaned in protest, buckled, then popped free in my hand. I put it on the floor and lit the duct with my flashlight. It was large, obviously a main conduit. It receded for about ten feet, then took a ninety degree turn to the left. I handed Maggie the flashlight, waved my open palm in invitation at the vent.

"You've gotta be kidding. I am not going into there."

"Trust me. I have a hunch. After you."

She sighed and shook her head. "Age before beauty," she said.

I gave her a look.

"Fine," she said, crawling in. "Grumpy old fuck."

We wriggled forward on elbows and knees. I tried not to stare at Maggie's bottom as it swished in front of me. A couple turns later, we reached another grill. Maggie played the beam through the slits into the darkness beyond.

"Some kind of larger space." She moved the light some more, trying to find edges. "Fifteen by fifteen, I'd say."

"A store room?"

"This vent's the only access."

"What's a room doing back here?"

"My guess is, under this chic morphinium shell is an older building. Probably extensively remodeled. Sometimes, when the architects lay out new floor plans, little useless trapped spaces like this happen."

"Useless," I murmured.

She gave the grill a shove and it clattered away into the darkness. We climbed in.

A foldable cot sat against a stack of supply bins, surrounded by empty wrappers and energy bars. A smartscreen was propped up amidst a mess of clothing. A hot plate, a couple lanterns.

"A rat's nest," said Maggie.

"For a human rat," I responded.

A whimper came from behind some boxes. I pushed them aside. A bespectacled man in suspenders and tweed pants cowered on thin haunches. Greasy strands of hair were plastered across his bald pate. The man blinked in the flashlight's glare.

"Dr. Crandall, I presume?" said Maggie.

I wrinkled my nose. "Be glad you can't smell, Maggie. This guy hasn't had a bath in weeks."

Back in the lab, we sat him in a chair. Maggie gave him a paper cup from a cooler. He drank greedily. Then he scanned his office like a worker reorienting himself after a long vacation. I put the smartscreen on the desk.

"No one's touched a thing," Crandall said.

Crandall blinked, heavy-lidded. The scientist was all angles. Sharp cheekbones and elbows and size thirteen feet. Somehow, the lanky frame held together. He had the air of a person so obsessed with his work that all other concerns, even food, were phantoms in the wind.

"I don't suppose either of you has a cigarette," he said.

"They're illegal," I said.

Crandall chuckled without moving his face. "A condemned man always gets a last cigarette."

"My name's Donner. I was hired to find you, not kill you."

"Donner. A detective, you say?" Crandall appeared to mull that over, disturbed.

Maggie whispered in my ear. "How do we explain this?"

"Explain what?"

"Finding Crandall here! I doubt this Struldbrug dame will let us off the hook for breaking and entering just because we found the guy."

"You think I'm going to turn this guy over to Nicole after what we found out about the Retrozine?"

"Then what are we going to do with him?"

"Right now I want answers. We'll figure the rest out later."

"Well, hurry it up, ace. If security makes half-hourly rounds, our goose is cooked."

But it was Crandall who started the questioning. "You say hired," he said. "Who hired you? Gavin?"

"Nicole Struldbrug."

Amusement narrowed his eyes. It was nothing pleasant. More like the satisfaction a kid gets from frying ants with a magnifying glass. "With the largest private security force in the country, she hires a private eye."

"No one was getting anywhere."

"Probably because it never entered anyone's mind you'd disappear on purpose," Maggie said. I shook my head. Then she smacked her forehead. "The security disk! It wasn't changed to hide the real time you left the building. It was to hide the fact that-"

"You didn't leave at all," I finished.

"Which means-"

"I doctored the disk," said the scientist, looking pleased with himself.

Crandall was a victim of the same affliction as Dr. Gavin-the arrogance of the brilliant, based on the premise that every obstacle in life could be out-maneuvered by a superior mind.

I hoped he never had to out-think a plasma rifle.

"I supervised the architect when he remodeled the lab," said Crandall. "I knew about the hidden space. I came out at night, read my assistants' notes, followed their progress. Do you know I could hear their conversations through the vent?" He sniffed. "I had no idea they despised me."

"Why hide?" I asked.

"When Dr. Smythe was murdered, I wasn't left much choice. Someone was assassinating members of our team."

"How did you know that?"

Crandall was silent.

"Why not go to the company for protection? Or the police?"

More silence. My bad feeling had turned into a nasty burning in the pit of my stomach. An act as extreme as hiding from everyone, for a whole month-the man had to have an extreme reason. "Who's trying to kill you, Doctor?"

His lips pruned up. "You've found me, fine. Return me to my employer and collect your little fee."

"Hakuri's dead."

He shook his head. "I heard. From talk in the lab."

No option but to go for the heavy artillery. "Retrozine," I said, smiling. "Great name."

The change in his face was astonishing. The prune dropped open to reveal scummy teeth.

"The youthing drug you've been testing."

"On people," said Maggie.

"Oh my God. Listen to me-"

Before Crandall could finish, someone spoke from behind us.

"Morris, honey, there you are!"

She stood silhouetted in the door in a worsted wool suit. The cream blouse was open to display a clasp of diamonds at her throat. Her brassy mane had been tucked up in a bun. Pale yellow kid leather gloves matched the handkerchief tucked in her breast pocket.

The three monstrosities in composite armor behind her held Thompson submachine guns-the kind with the round, oversized Type-C magazine made famous by gangster movies. The kind that took two hands to fire, went rat-a-tat-tat and spit shell casings everywhere. The kind that chewed you into hamburger.

Nicole waggled a finger at Crandall. "You had me very worried, Doctor." She turned to me. "Hey, Donner."

"Ms. Struldbrug."

"Nicole, please. We're all friends here."

"That's what I'm hoping."

"Brought along your talking mannequin, I see."

Maggie flinched.

"Nicole," I said. "Why are you here?"

"Now, baby, that was my line." She sashayed toward us. I moved forward to meet her. The outer lab was a less confined space. If things went south I'd want as much room as possible. Crandall and Maggie stayed close behind.

"If you'd wanted to see the lab," said Nicole, "all you had to do was ask."

"I did. Dr. Gavin doesn't like me very much."

She flicked cold eyes at Crandall, then past him to the open vent. "Been hiding in the walls, have we, doctor? I suppose you consider that clever." She ran a finger across the man's grizzled jaw. He flinched at her touch, as I had done. "Welcome back."

"Are you going to kill me?" Crandall whispered.

She didn't even bother to feign hurt or shock. "I've been trying to save you."

"Like you saved Smythe? And Hakuri?"

Nicole tapped her shoe impatiently. "Why would I kill my own scientists? Especially when they're on the verge of a breakthrough?" To me: "You believe me at least, don't you?"

"I'll believe you a whole lot more if you tell your boys to lower those guns."

"Do you like them? The outside is vintage 1928AC, the inside is pure plasma."

"Impressive. Planning to use them?"

"We'll see how the evening develops."

As if on cue, the security men moved forward in lockstep. The snouts of their Tommy guns raised to chest level.

She'd heard us talking. Enough, at least, to know we'd discovered Retrozine.

"Don't do anything rash, Nicole."

"Sorry, baby, can't hit the brakes now. Pedal to the metal, that's my motto." She withdrew a cigarillo from an enameled case and lit it with a matching lighter. The smoke hung next to her like a thought balloon. She was debating her options.

So was I. I didn't like any of them.

Then she noticed Crandall staring vacantly into the air, his tangled eyebrows working up and down like he was factoring pi to the twentieth decimal. "What's the matter? You get buggy in the wall, Doctor? Am I going to have to re-socialize you?"