Brad upgraded the Universe Treadmill.
The reason was simple: Brad had discovered that electricity derived from the Speed Force seemed suitable for everyday use, so he modified the Universe Treadmill into something resembling a hamster wheel.
The upgraded treadmill had a stronger connection to the Speed Force. Brad pushed Pietro onto the new "hamster wheel" under the pretext of training, claiming that the daily running regimen would help Pietro gain better control of the Speed Force.
Watching the silver lightning spin into a ring of light inside the hamster wheel, and the readings on the connected energy storage device skyrocket, Brad smiled in satisfaction.
"That should do it. You can come down now, Pietro."
Ordinary sound waves could not reach a Speedster running at high speed, but after accessing a telepathic mutant ability, Brad could easily transmit his meaning directly into the Speedster's mind.
Normally, Pietro would have grown bored long ago and jumped off the Universe Treadmill at the first opportunity. Barbara had promised to take him shopping for clothes today. Choosing outfits for everyday wear, a luxury once reserved for the upper classes of the Steel Domain, held an irresistible appeal for the boy.
Strangely, however, even after Brad transmitted his message, Pietro continued running at high speed without the slightest intention of stopping. In fact, he kept getting faster.
Then Pietro's fragmented mental signals reached Brad's mind.
"I...
...can't stop!"
"The Speed Force is acting strangely...
...feeding me energy. I have to keep running, or...
...it'll swallow me."
The hamster wheel's rotation had already exceeded its peak speed. Energy converted from the Speed Force poured continuously through the cables into the battery-shaped energy storage device.
Brad turned toward the "giant battery," whose stored energy was about to exceed its capacity, and scratched his cheek with his index