She walked past the row of seated board members, her cream-colored trousers brushing against the back of Dr. Aris’s chair.

My father followed two steps behind her, holding his leather briefcase like a shield.

“Derek,” my mother said.

Her voice was not loud, but it carried clearly in the quiet afternoon air.

Derek stopped what he was doing, a heavy wrench still gripped in his right hand.

His knuckles were gray with grease.

“Mother,” Derek said, wiping his brow with the back of his forearm. “What are you doing here?”

“Put that down,” she said, stopping just inches from the yellow safety tape surrounding the microgrid.

She looked at his grease-stained uniform with a mixture of pity and disgust.

“We are leaving,” she said.

I stepped down from the wooden platform, the soles of my shoes scraping loudly against the concrete.

“Mother, we are in the middle of a live technical demonstration,” I said, keeping my voice as flat and professional as possible.

“This is private property, and the board is waiting.”

Helen did not turn her head to look at me.