Undersea City by Frederik & Williamson Pohl

in a surface city—at first; until you noticed the Troyon tubes that give it light, set into the metal ceiling that hung forty feet overhead.
    We poked through the crowds around the tri-D theaters and the restaurants. There were plenty of people—civilians, crewmen from the sub-sea cargo and passenger vessels, uniformed men from the Fleet. I saw several cadets in sea-red dress uniforms, but none of them was Bob.
    We rode on a slidewalk along a circular street to the next radial, then hopped on a slide that took us back to the elevators.
    Harley gave his watch a calculating squint. “The dome has a hundred miles of streets,” he said. “With the slidewalks moving at four miles an hour, you’ll be about four working days searching the city—and then Eskow will probably be inside some building when you go by. Better give it up. Come on home with me.”
    I said, “Let’s try one more deck.”
    We went up to the next deck. The slidewalk took us past rows of shooting galleries and pin-ball machines and novelty shops that sold little plastic models of the dome in mailing cartons. We saw a lot of men in uniform. But none of them was Bob.
    “That’s all for me,” Harley Danthorpe said.
    I shrugged. He said persuasively: “Why not ride up to the next deck? That’s where my family lives. You might as well look there as anywhere else.”
    It seemed reasonable.
    We went up one deck more, and out a radial street that was crowded with expensive looking restaurants. We rode the slidewalk through the safety wall, into the residential octant where Danthorpe lived.
    The streets were wider there; strips of carefully manicured lawn were growing under the Troyon lights, beside the slidewalks. The apartment buildings glittered sleekly with wealth. The doors were guarded by expensive robot butlers.
    “Come in,” said Harley Danthorpe hospitably. “Stay for dinner. My father’s chef can—”
    “Thanks,” I said, shaking my head. Danthorpe shrugged and left me.
    I rode on around through the next safety wall.
    It was a different part of the city entirely. I was in the financial district now, and it was after business hours, the streets empty tunnels of plate glass and stainless steel and granite. It wasn’t a likely place to find Bob. I rode on, into the octant.
    This was a livelier section by far. It was the crowded residential section where the bulk of the dome’s population lived—not the lavish luxury homes of the Danthorpe family, but the clerks and factory workers, and the families of the Fleet and commercial sub-sea liner crews. It had no glitter, none at all. There were a few little shops on the deck, but the floors above were all apartments. Men in undershirts were reading newspapers on the balconies. Kids were shouting and running, noisily chasing after balls in the street; women in housecoats were calling after them.
    I couldn’t think of a single reason why Bob might be here, either.
    I had just decided to stay on the circular slidewalk, continuing until it returned to the shopping district again, when—I saw Bob!
    He was talking to a man, a wrinkled little Chinese—the man I had seen at our barracks!
    I was on the point of rushing up to him, and then, queerly, I stopped myself. Though I hated to admit it, it seemed that there was something going on here—something that involved my good friend Bob Eskow, in a way that I didn’t like. I was no spy, no private detective to take pleasure in shadowing a man and catching him at some evil act. But here was something that I didn’t understand, and I could not make myself step forward until I had a clue as to what was going on.
    And they were, in truth, behaving oddly.
    It was almost as though they were suspicious of being followed. They spoke briefly, then drifted apart. Bob knelt on the in-walk, fussing with his boots, looking covertly around. The little Chinese ambled a dozen yards away and fed a coin into a sea-chicle vending machine—and he, too, glanced