“Robin is on speaker with me, he has also had it. Have any of you explored outside of the reception area?”

They hadn’t. I told them about the puzzle and the weird string of letters and numbers.

“I suddenly want to go to sleep very, very badly,” said Andy.

“April, can you repeat the code you got again?” Miranda’s voice came out tinny from the phone’s speaker.

“Six, seven, six, four, five, F, zero, zero, four, D, six, one, seven, four.” It had stuck in my head so thoroughly that I didn’t even have to pause.

“It sounds like hex.”

“OK, what’s that?” Robin said.

“Hexadecimal. Like, our numbers are in base ten. Hexadecimal numbers are in base sixteen. In computer programming, every number up to sixteen is represented by a different symbol. So, it’s like zero, one, two, three, four, five, six, seven, eight, nine, A, B, C, D, E, F.”

“What?” I said.

“It’s not super easy to explain,” she responded. “It’s one of the very basic ways computers talk. It’s better because sixteen is two to the fourth power, and computers only talk in twos.”

“Still not making sense, but we believe you,” Andy said.

“OK, I guess the most important thing to ask is, is this just us?” I said.

“Who is most tired?” Robin asked.

“Probably April,” Miranda said, at the same time Andy said, “April,” at the same time I said, “Me?”

“Right, that was maybe a dumb question. April, can you go to sleep?”

“I mean, almost always.”

“OK, that’s your job. See what you can find out. The rest of us are going to do a bunch of research and see if we can figure out who else is having this dream and what it means. It all seems impossible.”

“I agree it is not possible,” said Miranda.

“And yet!” Andy added.

“OK, I’m going to go to bed! Good luck, everyone!”

* * *

—

When I was in middle and high school, I earned some extra money by finding people’s lost pets. The town in Northern California where we lived had about fifty thousand people, most of whom lived within a few square miles of each other. It started when I was volunteering at the Humane Society. I would walk dogs, spray out cages, clean litter boxes, and “socialize” (play with) the animals. Pretty great work, but it didn’t pay.

With fair regularity, a dog or cat would show up at the shelter and within the day someone would call asking after the pet. It was always a wonderful feeling, reuniting the pet with its owner. But we also got a lot of calls from people whose pets we did not have. I took this pretty hard. The employees at the shelter advised me to not get too involved, but I hated the idea that there was some beloved animal out there, crouched under a porch, maybe hurt or sick but almost definitely scared. And then there were the owners—often kids were involved. These people would do anything to get their pets back, including offering rewards.

Being a pet detective definitely sounds like a fake job, but I googled it and there were real people who did it. I emailed a bunch of them, saying I was doing a project for school, and interviewed them to find out more about their business. One woman was particularly candid, telling me that the real trick of being a professional pet detective was to get paid whether you found the pet or not, and definitely to get paid if you happened to find the pet after it had died. This, apparently, was fairly common. Pets get caught and stuck and starve, they stumble into traps meant for raccoons or foxes, and, more than anything, they get hit by cars.

I was fourteen, so I didn’t get paid by the day or anything, but I did always call the number to tell them I was on the case and to confirm that I would get a reward whether I found the pet alive or dead.

For the most part, this is extremely boring work. You learn as much as you can about the pet, its habits, and its fears, and then you walk up and down busy streets hoping to not find that the worst happened.

Most cases were boring, and the success of the occasional live-pet discovery was worth way more than the $200 rewards I’d get. Though, to be clear, the $200 rewards were a pretty big deal for me. But I had a few cases that were actually intriguing—cases with clues and odd characters and some legitimate human drama. It’s very important to learn a good bit about the owners. A surprising number of lost pets are actually stolen pets, usually by a friend or family member, often as some kind of retribution.

One of my weirdest cases stretched on for months. I was 90 percent sure that Andrea Vander’s Maine coon cat, Bitters, had just wandered off one day and found a different family. This happens occasionally with outdoor cats; they find someone they like better and just stop coming home. Andrea Vander was not a particularly lovely person, and if I were a cat, I probably also would have found a different home. But I’d knocked on every door within a half mile and found no sign of Bitters. I was at Vander’s house one day, pretty much ready to give up the case, when some food was delivered by a young woman in her twenties.

I watched as Andrea Vander, with great care, counted out the exact change of her delivery order, leaving zero cents extra for a tip.

“That looks good,” I said to Ms. Vander after the delivery driver had gone. “How often do you order from there?”

“Every day,” she said.

The next day, I ordered some food from that restaurant. The same delivery driver showed up at my house, and I made her a deal. I wouldn’t say or do anything at all if Bitters showed up at my front door in the next twenty-four hours. If that didn’t happen, she could expect to see me asking questions around her neighborhood very soon.

“She’s just so awful!” the woman whined.

“Shhhh . . . ,” I advised her.

Now, look, I know this doesn’t sound very high-stakes, but Bitters was home, I got my $200, and everyone was happy.

I tell you this story because, by the age of sixteen, I considered myself something of a talented detective. And at twenty-three, I figured I must be even better. I had solved and implemented the Freddie Mercury Sequence before anyone else even knew it existed. Of course, I did that with help, but that’s part of what a good detective does. I was feeling pretty proud of myself.

So when I finally got my ass to sleep after an hour of tossing and turning, I was ready to take the Dream on headfirst. I started out by wandering through the parts of the office building I could explore, avoiding only the receptionist, who seemed to be good at waking you up.

The door to the puzzle room was one way out of the reception area, but there was maybe another: An elevator stood on the opposite wall. I hadn’t considered it at first, but if I could go into the office, why not try that?

I pushed the down button and the elevator door opened immediately. It was a normal elevator, nothing special except the number of buttons. They climbed up both sides of the door, higher than I could reach. I thought about going up, but I’d already pushed down, so instead I punched the button for the ground floor. I had already looked out the window of the building onto the peculiar city; I wanted to see if maybe I could get into it.

The elevator opened into the cavernous lobby of a fancy office building. They all look different, but they all look the same. The floor was marble; the ceiling was thirty feet up. There were tables with flower arrangements, a big desk where security and check-in would go, art on the walls, and, in the center of the room, blown up double-sized, towering over the whole thing, was Carl.

Well, that was one mystery solved. Any chance that this was a somehow-unrelated impossible mystery was gone now.

What was conspicuously absent from the whole thing was people. Office building lobbies are central stations of human activity and movement. This place looked like it had been sucked out of reality and put into some kind of museum exhibit: “Here is an example of early twenty-first-century high-rise lobby design and decor. You can see the emphasis on stonework contrasted with meticulously maintained flower arrangements. The hard and the soft, the permanent and the ephemeral, but both costly, giving those who occupied the space a sense of high-class luxury.”

In fact, I would later note that the Dream’s entire landscape looked like some kind of diorama, constructed as a place to observe, not as one to occupy.

Anyhow, I overcame the desire to explore and instead moved through the giant room and then through the door. Outside was, again, a tremendous stillness, but an assault of conflicting styles. Directly across the street was an Arby’s, but not, like, a city Arby’s smashed into a row of retail storefronts. A free-standing normal-America Arby’s surrounded by its parking lot. Next door to the Arby’s, surrounded by a swath of knee-high grass, was a wooden church-looking building. No cross capped its steeple, but the slatted wood and the double doors centered on the front of the building made the sense that it was a house of worship clear.

None of these buildings alone looked weird; they were just dramatically out of each other’s context, especially considering the massive marble lobby I had just walked out of. I turned around to look at the building. After a few years living in New York City, you look up less, but now I craned my neck up and found that as high as I could see, there was no end to the height of the building I had just exited. I kept leaning back to try to see farther. Suddenly I stumbled, and then lurched to the side, and then was awake.