No one but Violet seemed to be interested in the empty foundation that Dr. Moore’s laboratory had cast off when it reached for the skies. You could see why. On this block alone there was one laboratory that had slumped, recently, into a misshapen pile of stone blocks; there was another former laboratory that had apparently exploded, driving shattered concrete panels into the walls on either side. Laboratories came and went in the Experimental Research District: it’s just that normally they went in all directions. Doctor Moore’s was the first to decide, for whatever reason, that it ought to go up… and stay there.

Someone had capped off the gas main, but the water pipes were shooting a geyser twenty feet in the air and this didn’t seem to concern anyone except for some small, orange creatures that were more or less like salamanders. They were swimming and basking in the puddles. Violet took a moment to wonder about the gas and water systems. They were possibly older than the District, since you’d never get a maintenance crew in here to service them. Then she turned to face the laboratory of Professor Wilcox. It was right next door.

Professor Wilcox’s lab was built to last, which is typical of the buildings in the District precisely because they never do last. Like its neighbors, the building was constructed of huge panels of reinforced concrete that hid its massive slabs of lead shielding. There were some unusual shock absorbers, each about ten feet in diameter, that braced the walls in deep slots that were cut into the laboratory’s moat. A narrow walk bridged the moat and met the steps below the blast doors that guarded the entrance. Spidery fire escapes hung optimistically from the roof. On the right side, which faced a new and unscarred lab, Violet saw scorch marks and soot that had penetrated the surface of the concrete and stained it to a darker, smokier grey. On the left, of course, was Dr. Moore’s gaping foundation.

Violet made no effort to soften her metallic footsteps on her way up Professor Wilcox’s steps. Her feet rang out like trumpets. Her hand, when she pounded on the blast doors, left deep scrapes in their hardened steel. “REGISTRY OF PATENTS,” she shouted. “OPEN YOUR DOORS.”

After a pause, the blast doors edged slightly open. She could see Professor Wilcox in the shadows within. “You’re not in uniform,” he said. “How do I know who you are?”

Violet reached straight through the narrow gap and seized the scientist by the throat. “OPEN YOUR DOORS, YOU FRAGILE HUMAN PERSON.”

This was so effective that several other doors opened up along the street. But Violet only cared about the one. As soon as Professor Wilcox had complied, she stepped straight in without releasing his throat.

His feet were trying to get a grip on the floor, but it was hopeless. He ran in place while Violet held him high. She looked at Professor Wilcox’s assistant, who was staring at her from the hall. “CAN YOU EXPLAIN WHAT HAS HAPPENED TO DR. MOORE’S LABORATORY?”

The laboratory assistant, who was cowering anyway, shook her head slightly faster than the rest of her body.

“THEN GO.”

The assistant went. Violet returned to her examination of the professor.

“Now,” she said more quietly, “I’d be grateful if you would explain what you’ve done to Dr.Moore’s laboratory. Then I expect you to reverse the process. One of our investigators is trapped inside. Also, I have personal problems that I want to resolve in a very short amount of time.”

The professor denied any involvement with the floating laboratory. “I’d never endanger a Patent Investigator,” he insisted. “I depend on my patents… you know I do.”

“And what about Dr. Moore?”

Professor Wilcox looked down at the floor. “She’s… she’s not a good neighbor. We’ve had problems.” His eyes came up again and locked on Violet’s. “She stole my invention!”

“That matter is under investigation,” she said reasonably. “We have a system in place. Investigator Bowman was interviewing Dr. Moore when the laboratory… launched.”

“Investigator Bowman is in there?” The professor seemed genuinely worried. “I had no idea!”

“WHAT DID YOU DO?”

When she raised him higher and shook him, Violet could see that she had gone too far. He just kept on insisting that he was innocent of any wrongdoing.

Then the doorbell rang.

At first, Violet was surprised that there was a doorbell. But it couldn’t be anything else. So she kept Professor Wilcox dangling from one hand and hit the door release with the other. The blast doors swept open to reveal a young woman in Courier Service livery. She had a package, tied with a string, that bobbed lightly overhead. It was about two feet wide and three long, but it was obviously lighter than air – so much lighter that the courier was wearing massive osmium overshoes and belt weights to hold her down.

“Um, delivery for Professor Wilcox?” The courier looked past Violet to see the professor, choking and sputtering, where he hung from the robot’s hand. “If I’ve come at an inconvenient time….”

“You’re making an inertrium delivery?” Violet asked.

“Yes, ma’am. Like I was saying, I could always come back later….”

“No, please, don’t trouble yourself.” Violet looked at the professor. His face was darkening from red to purple. “Would you sign for this package, please?”

Professor Wilcox struggled with the pen and the shipping invoice as Violet continued.

“Have you made a lot of inertrium deliveries to this address?”

“Um, yes ma’am. Every day for, oh, a little over a year now.”

The professor handed the receipt to the courier, and she gave him the string. The lighter-than-air metal pulled him upward. Violet heard him gasping for breath now that his weight was relieved. She tossed him down the hall and closed the doors, then made herself useful by carrying the courier’s osmium overshoes down the steps. “I’m Violet,” she said.

The courier got back on her scooter and unhooked the osmium weights from her belt. There was an inertrium trailer bobbing up behind the scooter, piled with parcels. “Grace Keaton, ma’ – Violet. Pleased to meet you.”

“I’m with the Registry of Patents. Just a little disagreement.”

Grace released her ground straps and the scooter shot upward. She tapped the controls for her upward-facing jets, and the scooter sank back toward the pavement. “I can see how that would happen,” she said. “Did you need me for anything?”

“No. Thank you, Miss Keaton.” Violet watched as the courier took off en route to her next delivery. Then she stepped around Professor Wilcox’s laboratory to take a close look at Dr. Moore’s foundations.

She found the tunnel without much trouble. It was filled with water from the mains, so she hadn’t noticed it before. The tunnel would have opened up into Dr. Moore’s basement back when the basement was still there. Violet lowered herself into the water, submerged, and followed the tunnel back to Professor Wilcox’s basement. Then she went up the stairs and terrified the professor’s laboratory assistant by coming through the basement door. Water poured off her enameled body.

“I need to use your televideo phone,” she said. “Sorry about the floor.”