“Mind telling me what this is all in aid of, Carpenter?”

Isiah Carpenter turned around, and saw his boss, Director Berntessen, standing right behind him. He was sitting in front of a desk, surrounded by sacks, next to a large open area, well-lit and floored with what seemed to be foam padding.

“Oh, hello, Director. You're up and about today.”

“Yes. And now I come to the lab, and find you not working on ponifcation serum, but playing with... sacks?”

“Burlap sacks!” Carpenter corrected cheerfully.

“You've got about thirty seconds, Isiah.”

“Sheesh, chill the beans, Director.” Carpenter spun his rotating lab stool around, and faced his employer. “So; we've got some downtime while the grunts find another volunteer, so we decided to do a little experimental science.”

“On what?” Berntessen poked a sack with his walking stick. “They're sacks, hardly relevant.”

“You'll see,” Carpenter promised. “Twilight? Richardson?”

“For the record,” Twilight Sparkle protested, as she walked out from behind a screen, “I do not like these tests.”

“Oh, come on,” Carpenter wheedled, “It's perfectly safe, and we can't talk any of those pegasus guards into doing it.”

Twilight muttered something uncharitable, but the purple unicorn sat down in the middle of the padded testing area nonetheless.

“For the record,” a second voice stated, “I don't really care for this test, either. Sacks are so...”

“Shush, Bruce.” Carpenter rolled his eyes as a slim man in a lab-coat walked out from behind the other screen. “You're not even getting distressed. Or you shouldn't anyway. You're not claustrophobic, right?”

“It's the look of the thing, Carpenter,” Bruce countered, “Sacks are not, will not be, nor have they ever been in vogue, as they say.”

“Sit down and shut up.”

The assistant's assistant sighed, and sat down next to Twilight.

“So, what's the deal?” Bernetessen said, irritably.

“Watch. Jameson, please step forward, and place a sack on Robertson's head.”

With a stiff gait, a metallic humanoid marched out from behind Carpenter and Berntessen, taking a sack from the table as it went – with a practiced motion, the robot placed the sack over Bruce's head, and the human sat there, not moving.

“Robertson! Rating of one to ten, how upset are you?”

“Two.”

“So...” Berntessen looked at Carpenter, questioningly.

“He's not afraid of the sack.”

“How does this-”

Carpenter raised a hand, cutting Berntessen off. “Jameson, please attempt to place a sack on Twilight Sparkle's head.”

The robot turned around, and returned to the desk to retrieve a sack. Twilight looked antsy.

“So, um. Isiah. Can... can we not do this? I don't feel safe.”

“It's totally safe, Twilight,” Carpenter said, “Fresh from the auto-fab. Now, just... sit still. And try not to rip Jameson in half with your magic, again.”

The robot rumbled. “I did not like being torn into two pieces horizontally.”

“So. Sack.” Carpenter nudged Berntessen. “Observe.”

The sack went over Twilight's head, and she began to shake.

“Twilight. On a discomfort scale of one to ten, please rate your discomfort right now.”

“ELEVEN! SIXTEEN! TWO THOUSAND AND SIXTY THREE! LET ME OUT!”

“Remove the sack, Jameson.”

The sack was removed, and Twilight sat there in the middle of the mat, shaking like she'd been shell-shocked.

“Twilight freaks out around sacks?” Berntessen concluded.

“Not just her. EVERY pony. Even the guards tried to shy away when I tried to sack 'em.”

“Right, so ponies have an innate fear of sacks. How is this relevant, again?”

“I figure we can use it as a litmus test of sorts for ponification – when the converted ponies refuse to put their head in a sack, we're on the right track.”

“That's it?”

“Oh, and I wanted an excuse to get Twilight in the sack.”

“Isiah!” Twilight exclaimed, rapidly turning red.

“That was awful, Doctor,” Berntessen shook his head slowly. “You're lucky I don't pay you for your pun-making ability.”

“You don't pay me at all, Director, remember?”

Berntessen turned and began to hobble away. He paused at the doorway.

“Report. On my desk. By tomorrow.”

Carpenter and Twilight watched the old man go, and Twilight sighed.

“Did you really have to say that?”

“Yes, Twilight,” Carpenter stated levelly, a smile creasing his face. “Yes I did.”