40 minutes, give or take: how long they have to fix things when they go wrong. Always this planet, always this species. The repairman sighed.

The computer code for the universe had been simple enough, and then these damn humans started tinkering with it, testing the boundaries, digging deeper into the pure math of existence. So elegant at the beginning, all the hacks and patches applied to the code now made a towering unstable pile that could collapse at any moment. So finally the censor loop had been added. And the repairmen had been sent down into the simulation. Human bodies, human minds, some extra powers.

Today’s problem: several tons of mass had accidentally been deleted. The data structure representing a certain boulder under Central Park got lost or was stuck in a buffer somewhere… but that didn’t matter. The repairman had less than half an hour left to bring in a replacement mass, put it in place, and update the relevant memory pointers. Had to be done right, and on time.

E=mc^2, after all.