Download complete. Update installing now, said Robert's brain, translucent over a corner of his vision. This may take a while, it continued, and require several restarts. Please make yourself comfortable. "What?" Robert mumbled. He'd been heading out the door when he'd absently approved a recommended update to his brain. The little progress tracker had hit one hundred percent just before he lost reception in the subway.

Robert sat back and lazily cursed the software company. He usually listened to an audiobook during his subway ride. He was just getting bored when the busy train changed.

The train was still, silent, and empty, and Robert was on the floor. Robert looked around, blinking. Update installation complete. Standing up, he got dizzy and fell. He tried again, slower, but he couldn't make it more than a step without tumbling. Something was wrong with his balance. The brain update had screwed up his proprioception. He needed to revert to the previous version if he wanted to get out of here.

This is why I keep a backup image of my brain state, he thought, and he reached out for it through the cloud.

That's when he realized he still didn't have any reception.