Lin Mei’s red grease pencil snapped cleanly in half between her fingers as the vibration under her boots spiked.
Across the thirty yards separating them from the Master Control House, the wet concrete apron hummed like a giant, angry hornet trapped under glass. Concentric ripples of electric blue light -- pure St. Elmo’s fire -- spread outward from a shattered porcelain bushing atop Transformer Bank #2.
Every time a pulse of thirteen-thousand-eight-hundred-volt fault current surged through the saturated concrete, the water in the rain puddles hissed and turned to gray steam.
Lin Mei knelt beside the right wheel of Mobile Register Annex #04-B, her thumb rubbing the chalky wax of her broken pencil.
Her sharp brown eyes tracked the glowing blue rings on the wet slabs. “Look at the field geometry, Victor,” Lin Mei said, her voice taut with mathematical precision. “The ground fault isn’t spreading evenly.
It’s radiating outward in concentric equipotential circles. The voltage drops by roughly four hundred volts with every foot of distance from the cracked bushing.”
“A classical step-potential gradient,” Dr. Victor Corvo replied, standing at her shoulder. He swirled the cold black dregs of his Pyrex beaker, his velvet baritone completely calm despite the deadly blue sparks crackling twenty paces away.
