to you again."
The other's smile was quite dead. He muttered, "I'll get you a rod, Officer."
The guide rod was set for Department CG, Section 2. What that meant in factory terminology, Baley didn't know. He didn't have to. The rod was an inconspicuous thing which could be palmed in the hand. Its tip warmed gently when lined up in the direction for which it was set, cooled quickly when turned away. The warmth increased as the final goal was approached.
To an amateur, the guide rod was almost useless, with its quick little differences of heat content, but few City dwellers were amateurs at this particular game. One of the most popular and perennial of the games of childhood was hide-and-seek through the school-level corridors with the use of toy guide rods. ("Hot or Not, Let Hot-Spot Spot. Hot-Spot Guide Rods Are Keen.")
Baley had found his way through hundreds of massive piles by guide rod, and he could follow the shortest course with one of them in his hand as though it had been mapped out for him.
When he stepped into a large and brilliantly lit room after ten minutes, the guide rod's tip was almost hot.
Baley said to the worker nearest the door, "Francis Clousarr here?"
The worker jerked his head. Baley walked in the indicated direction. The odor of yeast was sharply penetrating, despite the laboring air pumps whose humming made a steady background noise.
A man had risen at the other end of the room, and was taking off an apron. He was of moderate height, his face deeply lined despite his comparative youth, and his hair just beginning to grizzle. He had large, knobby hands which he wiped slowly on a celltex towel.
"I'm Francis Clousarr," he said.
Baley looked briefly at R. Daneel. The robot nodded.
"Okay," said Baley. "Anywhere here we can talk?"
"Maybe," said Clousarr slowly, "but it's just about the end of my shift. How about tomorrow?"
"Lots of hours between now and tomorrow. Let's make it now." Baley opened his wallet and palmed it at the yeast farmer.
But Clousarr's hands did not waver in their somber wiping motions. He said, coolly, "I don't know the system in the Police Department, but around here you get tight eating hours with no leeway. I eat at 15:00 to 17:45, or I don't eat."
"It's all right," said Baley. "I'll arrange to have your supper brought to you."
"Well, well," said Clousarr, joylessly. "Just like an aristocrat, or a C-class copper. What's next? Private bath?"
"You just answer questions, Clousarr," said Baley, "and save your big jokes for your girl friend. Where can we talk?"
"If you want to talk, how about the balance room? Suit yourself about that. Me, I've got nothing to say."
Baley thumbed Clousarr into the balance room. It was square and antiseptically white, air-conditioned independently of the larger room (and more efficiently), and with its walls lined with delicate electronic balances, glassed off and manipulable by field forces only. Baley had used cheaper models in his college days. One make, which he recognized, could weigh a mere billion atoms.
Clousarr said, "I don't expect anyone will be in here for a while." Baley grunted, then turned to Daneel and said, "Would you step out and have a meal sent up here? And if you don't mind, wait outside for it."
He watched R. Daneel leave, then said to Clousarr, "You're a chemist?"
"I'm a zymologist, if you don't mind."
"What's the difference?"
Clousarr looked lofty. "A chemist is a soup-pusher, a stink-operator.
A zymologist is a man who helps keep a few billion people alive. I'm a yeast-culture specialist."
"All right," said Baley.
But Clousarr went on, "This laboratory keeps New York Yeast going. There isn't one day, not one damned hour, that we haven't got cultures of every strain of yeast in the company growing in our kettles. We check and adjust the food factor requirements. We make sure it's breeding true. We twist the genetics, start the new strains and weed them out, sort out their properties and mold them again.
"When New Yorkers started getting strawberries out of season a couple of years back, those weren't strawberries, fella. Those were a special high-sugar yeast culture with true-bred color and just a dash of flavor additive. It was developed right here in this room.
"Twenty years ago Saccharomyces olei Benedictae was just a scrub strain with a lousy taste of tallow and good for nothing. It still tastes of tallow, but its fat content has been pushed up from 15 per cent to 87 per cent. If you used the