“What about insects?” Ben asked. “Don’t moles eat insects too?”

Professor Zappencackler waved him off. “If they’d rather have insects, why come here? Either worms are a delicacy to them, or the sheer size of Fenwick’s worms means that they can feed their city for months; maybe years, if they breed the things.”

The mole people had run their drilling machine clear out of the floor. Its huge drill was aimed at one of the worm enclosures.

“I didn’t know I’d made them smell good,” Fenwick was saying. “Who knows what smells good to a mole person?”

Violet patted him on the back. “Well, I guess we know now,” she said. “You’ve managed to create a mole attractor of unprecedented power.”

“Yes… I have, haven’t I?” The boy’s face brightened.

“Now we just have to figure out how to make a mole repellent that’s even more effective.”

This was the problem, all right. Ben was making an inventory of the devices the students were carrying. “We could try something with odors,” he suggested. “Some smell that the moles just can’t stand. I think their helmets might even be concentrating the odors around them, like loudspeakers.”

“That would explain the suits and helmets,” Professor Zappencackler said. “Isolation from most odors, concentration of the most vital. It probably has something to do with the way they’re communicating.”

“So a powerful smell might repel them and prevent them from talking to each other….” Ben handed back the Encapsulated Note-Taking Recording and Retrieval System. “Don’t let them catch you with that during the exams,” he advised. The young woman who’d been carrying it slipped it back into her pocket and looked sidelong at the Professor.

“It sounds like you could have used one of these,” she whispered.

Ben chose to ignore that.

“But it all goes sideways if the worms get out,” said Fenwick. “I could make a break for it, run upstairs, get my Worm Handler Suit. It’s impervious to their venomous spines.”

But a look out at the crowd of mole people showed that this would be a suicide mission. Even the students in the upstairs galleries had drawn back from the railings after a few well-places shots from the moles’ ray guns. Someone was whimpering in the gallery directly above.

“At the very least,” said the Professor, “we need to stop them from using their drilling machine on the tubes. Maybe if they can’t get at the worms they’ll just give up and go away.”

Three of the students were removing the hinges from the hallway door. That ought to keep the mole people from sealing them in. It would also leave them exposed to fire from their ray guns, Ben thought.

“Say,” he said, “what’s the range on that Spherical Obfuscator?”

One of the students handed it to him. “You can get three or four people in there,” she said. “Maybe six, if they’re not claustrophobic.” She was looking at Ben as though she figured he was really, really claustrophobic.

“Six, then,” he said with a grim smile. “Six of us can sneak up on the drilling machine and take it over, if we’re concealed by the Obfuscator. We just close the hatch behind us, and they’re stuck outside.”

Everyone looked at him. “You know,” Fenwick whispered, “he really doesn’t seem that… backward.”

Violet slapped the side of Fenwick’s head that Zappencackler hadn’t slapped earlier. “Show some respect, young man.”

Since a slap from Violet’s steel hand wasn’t anything to joke about, young Fenwick showed something that looked like respect. Pained respect, maybe, but Ben had to take it where he could find it around here.

“So me, and Violet, and the Professor, and maybe Fenwick – in case his worms get loose – and a couple of you…?”

Only one – the young woman who’d brought the Spherical Obfuscator – volunteered.

“Five might do it,” Ben allowed.

With its hinges removed, the three students at the door were holding it in place so the mole people couldn’t see them. The five members of the Mole Persons Repellent Squad gathered together in a tight squeeze. The Spherical Obfuscator whined into life, and they were surrounded by a globe that projected whatever was visible from the back side of the sphere, as you faced it, onto the front. They were now effectively invisible. “Let the door go now,” Ben whispered, and it swept out of their way. There was a minor problem when it swept back, just a little too soon, but Fenwick contained his grunt and then they were out on the atrium floor.

From the inside, the Sphere was a little confusing. In front of them they could see a perfect image of what was actually behind them, and it was only behind them that they could see where they were going. So the group of five pivoted in place inside their concealing globe and walked backwards, sneaking up on the drilling machine. Its motor was chugging softly while the mole people approached the right-hand tube with their worm crooks extended.

The Mole Persons Repellent Squad crept under the shadow of the drilling machine and positioned themselves below its open hatch. There was no way they’d be able to get through the hatch while walking backwards, so they waited until the mole people had reached the tube before they switched off the device and leaped, one by one, into the cabin.

This exposed the flaw in Ben’s plan. A crew of four mole people in their bronze and leather suits were hunched over the machine’s controls. Although they seemed quite surprised to see a party of five join them, they pulled ray guns from their holsters and neatly surrounded Ben and his companions. One, who seemed to be their leader, made a couple of emphatic meeps.

Ben raised his hands over his head. “We come in peace, ladies,” he said. Then, more quietly, he added “Everybody try not to smell like a worm.”

Without the mole people’s tiny, agile hands at the controls the drilling machine’s motor ascended into a dangerous whine. They all stumbled as it lurched forward, its rotating blade driving straight at the right-hand worm tube. Inside the tube, the worm recoiled; the mole people that faced it stepped back in dismay.