I learned her name on the last day. Marta.

It was the smear that made me pay attention. The same panel, the same motion, the same result — the glass returned to invisibility, the sea and sky restored to the surface, the mark of human contact erased.

I asked her where home was.

“A city in Ukraine.”

She said it without elaboration.

I asked her what it was like to work on the most advanced sustainable vessel afloat.

“It is like being inside someone’s idea of the future,” she said.

“The idea of the future is very clean.”

She looked at the panel she would clean again this afternoon.

“The future itself will require cleaning.”

She picked up her cloth and moved to the next panel.