The lunch crowd was just starting to trickle into the cafe as Max waited for his muffin. He had hoped to avoid the rush, but it was beginning earlier than he'd expected. It was just past eleven and the tables on the sidewalk were rapidly filling. The crowd was young, primarily college age kids and a few professionals, and even some kids who looked as though they should be in high school. Listen to the Chapter 21 podcast with roboreader Sangeeta. Max lowered his head and studied the wadded bills on the table to keep from catching anyone's eye, in the unlikely event that any of the arriving patrons knew him from campus. He picked the bills apart slowly and spread them flat on the checkered tablecloth. It had been so long since he had used paper money that Max almost didn't recognize the currency. All four were ten-dollar bills. They were old, worn, and crinkled. Someone had written on the least crumpled bill. The handwriting was jagged and juvenile, and he was having a hard time making out what it said. He could feel the numbers of the patrons swelling around him. He recognized the sound of one-sided conversations that meant many of them were chattering on cell phones. He glanced up briefly to see that others were gathered in small groups. There was an excited buzz in the air. Max had the impression that there was more to the activity than hungry people in search of lunch. As he turned back to the writing on the bill, a skinny kid engaged in an animated phone conversation bumped roughly against Max's table. He mouthed an apology and continued into the throng surrounding the cafe. Every seat was taken at the outdoor tables, and more people were on the way, strolling down along the sidewalk or dropped off at the curb by cars on auto pilot. The flow of customers had turned from a trickle to a flood, and was still building. This was definitely not a normal lunch crowd. Max dropped the wad of bills the lunatic had given him on the table and began rapping his fingers lightly on his thigh. The crush of bodies was making it hard to breathe. Max tried not to think about it, but he was continuously being jostled as more and more people arrived. He placed his hands open on the table and pushed down as if, at any moment, it might fly away and carry him with it. He stared at the bill in front of him, and struggled to stay calm until his muffin arrived. Someone, probably the lunatic, had written a across the president’s face. , "U r 6e1ng w4+ch3d." It was clearly a novice attempt at shorthand for "You are being watched." It was just the sort of thing he would have expected to find on money carried by a guy who wore a metal hat. On the other hand, thought Max, it was possible that the note was meant for him. "Nonsense," he said to himself, while glancing up at the wall of bodies that surrounded his table and slopped over into the parking lot. It seemed the lunatic’s paranoia was contagious. Surely the note wasn't for him. On the other hand, the man had insisted that he count the money, perhaps to get him to notice the message. Still, why should he worry about paranoid missives from a deranged fruitcake? He covered the bill with his hand to hide it from anyone looking over his shoulder. After a few calming breaths, he lifted his palm enough to peek at the message again. A shudder ran through him when he found that the writing had changed. It read "\/\/3'r3 h3r3 2 h31p.” Max snatched up the bill. It looked like plain old-fashioned money, as far as he could tell. But paper money didn't have shape-shifting messages on it. He was still trying to make out the new message when it shifted again. The writing, still in that childish hand now read "d0n+ f34r +h3 fl45hm06." Max blinked and slowly translated the script. "Don't fear the flash mob." He frantically scanned the wall of bodies that surrounded his table. Flash mob? What the hell is that? Somewhere in the noise of the crowd, amid the laughter and shouts, he imagined the waiter trying to make his