“Ex. Look at it,” Aubrey said.

Ex stepped out of the protective circle of red chalk drawn on the carpet, squinted at the runes and figures on the lock, and said something crude.

“Perhaps we should reconsider our approach,” Chogyi Jake said. “What if we began with the Itiru meditations, and then invoked the Mark of Lavavoth?”

“Not Lavavoth. South-southwest is a red herring,” Ex said. “I just don’t know what it’s distracting us from.”

It was a little after three in the afternoon, and the condo was trashed. Ex had stripped back as much of the drywall out of the hidden doorway as he could, and it left everything covered in a thin plaster dust. Everything smelled like it. The air tasted of it. On the plus side, we’d made more progress in the last three hours than we had in the first three days in Los Angeles. On the minus, the strain was telling. Tempers were starting to wear thin, my own included.

While I let the three of them work it out, I went to my bedroom. The black electronic key to the minivan sat on the table beside Aubrey’s wallet and cell phone. I picked it up, tossed it twice in the air, and headed back into the occult construction site.

“I’m heading out for a while,” I said. “Anyone need anything?”

“Green tea,” Chogyi Jake said at the same time Aubrey called out “Cleaning supplies.” Ex only looked sour and stared at the sigils on the locks. I scooped up my backpack and my laptop case, and I left.

As the elevator sank down to the garage level, I let myself sag. I felt frustrated. I felt tired and on edge. I felt like some part of me that I couldn’t quite control was pacing in the back of my head like a tiger in a cage. I stepped into the semiopen air of the parking garage, muggy air pressing at my face and the back of my neck. My footsteps echoed, and I realized I half expected someone to jump out of the shadows and attack. Or maybe a bunch of people, all breathing together. More than that, I sort of wished they would.

I got into the minivan with something like disappointment and realized I didn’t actually know where I was going. I had the general intention of shopping or seeing the sights or doing something to burn off some of the growing energy, but I hadn’t Googled directions to anyplace. I hadn’t even asked Harlan where the best local deli was. My options were to go back in or go forward without a clear idea where I was headed.

Or call the local expert.

Kim answered on the fourth ring, and for a few seconds I thought she was her voice-mail message. By the time I regained my conversational footing, Kim was already delivering a status report.

“I e-mailed Oonishi the questions,” Kim said. “Honestly, though, I don’t know how long it will be before we get the results. The others are right. He’s starting to regret calling you in.”

“Nothing like getting what you asked for,” I said. “Where are you right now?”

“I’m on campus. I just finished my lecture.”

“Lecture? You’re taking classes?”

“I’m teaching them. You don’t think they’d pay a mere PhD to do full-time research, do you?” she said, and the bitterness in her voice made it clear that wasn’t how it worked.

“Parasitology?”

“I wish. Cell biology. Introductory cell biology. There’s only enough interest for a real parasites section every two years or so, and so far I’ve had to co-teach with an MD from infectious diseases. It’s not really the same thing, but having a chaperone keeps me in my place. Why? Is something the matter?”

“No,” I said. “I just thought you’d be at Grace.”

“After yesterday? Not a chance. When we know what’s going on, I’ll consider it.”

“Can you do that? I mean just stop showing up there and not get fired or something?”

“No, I’ll get fired eventually. Unemployed is better than beaten to death.”

I laughed. I didn’t expect to, it just happened. Kim might have had the coldest, least sentimental mind I’d ever met. After a solid year of Ex’s weird paternalism, Chogyi Jake’s studied compassion, and my little romantic roller coaster with Aubrey, just talking to her was like seeing the world through new eyes. Of course she wasn’t going in. I’d assumed she was because she wasn’t at the condo. I didn’t know why I’d fallen so easily into the idea that on one side there was Grace Memorial, and on the other there was me and the guys with room for nothing else.

“Well, if you’re ditching work and have a few spare hours, I could use some help.”

“Did something happen?” she asked.

“No. Well, yes actually. But what I really need is to get out from underfoot while the guys work through something. I’ll tell you all about it when I pick you up. But the thing is I don’t know the city. Where to get a vacuum cleaner. Like that. And anyway, I could use the company. If you’re up to it.”

“All right,” she said. “Come get me.”

She gave me the address of a coffee shop. I gave it to the GPS and told her it would take me fifteen minutes to get there. She told me to expect thirty with traffic. I started the car, turned up the ramp, and headed out onto the streets of Chicago with only a reassuring, fake-British computer voice to guide me. Haze grayed the blue of the sky, softening the sunlight and bringing the infinite bowl of air a little closer. Traffic on the gentle left-then-right curves of the Kennedy Expressway was thick, but not as suicidally impolite as Los Angeles had been. Still, I found myself watching the other drivers carefully while the GPS told me where to go.

It almost worked. If it weren’t for Bell Avenue ending about twenty feet before it hit Taylor Street and making my last turn impossible, it would have been twenty minutes. I parked on Bell and walked the rest of the way. All the buildings were brick, two stories at the least, three at the most, and crowded up against the sidewalk. A busker with a ukulele sang a Tom Waits tune as I walked past. The breeze that cooled my cheeks and brushed back my hair smelled like car exhaust.

The Bump & Grind Café didn’t live up to its lurid name; it was all fresh coffee and baking apples. A flat-screen television was showing an art film that I remembered having heard about but had never actually seen. A few computers sat around, apparently for the free use of anyone who bought a coffee and wasn’t surfing for porn. And Kim sat at a table by the window. Half of a latte rested in front of her, the film of milk on the glass matching the hazy sky. Her purse was tucked under the chair, her head bent over a book.

For the space of a heartbeat, she didn’t see me, and I caught a glimpse of who she was when she thought no one was watching. Her clothes belonged on an older woman, neat, professional earth tones. Her pale hair gave the impression of being touched by gray, though I was pretty sure it wasn’t. Her gaze was focused, intent, closed. The softness at her jaw and the first, faint wrinkles at her neck reminded me of how my mother had looked when I was still a girl. And there was something else too; she had the same air of waiting for something she knew wasn’t going to come.

She looked up and nodded, and the impression vanished. She was once again my familiar, hard-edged Kim.

“So what’s happened and why do we need a vacuum cleaner?” she asked instead of saying hello.

While we walked back to the minivan, I brought her up to date, not just on the discovery of the secret rooms but on Los Angeles and the Lisbon notations—DC1 and YNTH—with our assumption that the first meant high security and the second being anyone’s guess. She listened with her head canted forward, like she was leaning into my words.

“What about the image enhancement on Oonishi’s data set?” she asked when I was done.

“Already uploaded.”

“Do we have an estimate of the time it’s going to take?”

“No,” I said, pulling out onto Polk. “We’ll know when we know.”

She nodded once, but she didn’t look pleased. I felt a little tightness at the back of my throat, like I’d gotten a bad grade on a paper that I’d been proud of. Maybe hanging out with her hadn’t been a good idea.

“Problem?” I asked, my tone carefully neutral.

“We’ve got too many tests and not enough data,” she said. “I wish we’d gotten into Eric’s secret rooms before we did the work for Oonishi. If there’s anything useful in there at all, it’s going to change the questionnaire.”

“It isn’t like Eric left us directions.”

“God forbid,” Kim said. “That man never let anything by if he could help it.”

“Did you love him?” I asked. I hadn’t meant to. I hadn’t even wondered until I saw her there in the café, waiting for something. “I mean, I know you and Eric—”

Kim took a quick breath, shrugged, and answered just as if I’d had any business asking.

“No, I didn’t. I don’t know why I did what I did. At first, I thought it was only that we were confined in the same cabin for too long, and humans act like that. But then after, when it kept . . . happening. Well, I didn’t love him. He didn’t particularly like me. The sex wasn’t very pleasant. It was just something we did. I rationalize it now. I say that I was lashing out at Aubrey or I just don’t have a very healthy attitude toward men or it was a self-destructive moment, but I honestly don’t know why I was with him.”

“You never told Aubrey,” I said.

“No.”

I turned the minivan up onto the Eisenhower Expressway, gunning the engine to bring us to speed.

“I didn’t either,” I said.

“Thank you.”

The traffic slowed, the first deadening congestion of the coming rush hour. Kim leaned forward, looking up into the empty sky.

“You still in love with him?” I asked.

“I miss him. But I know why we aren’t together. I don’t have to like it, but I’m all right. I’m glad the two of you are together.”