The white room was full of long, low tables, stretching as far as he could see. People hunched miserably over their work. A seat in front of him was empty.
"I don't understand," he quavered.
His neighbor glanced up. "Pair up the quarks - they snap together, see? - and fit them into the pattern. You're new, so you're working Hydrogen for now. Make sure you don't fuck up the protons."
The man smiled tightly. "What, you thought you got all that matter and time and space for free? You used it when you lived; now you gotta pay it forward."