The Wall had been part of Dragon's life since the day he was born. It was visible from every part of the barrio, the grey concrete of the Wall stretching along the northern horizon. At night, bright lights shone down from parapets, illuminating the Death Zone that ran parallel to the Wall. During the day, dark figures could be seen at the top of the Wall, moving back and forth monotonously.

A great body of lore had built up around the Wall. Some of it was indisputable, like never enter the Death Zone. Dragon had seen the bodies of those who had broken that rule, left lying to rot and be consumed by rats and flies. Not building higher than three stories was something that nobody could agree on. Yes, the taller houses in the barrio would often collapse; but that might happen for any reason. As to what was on the other side of the Wall - nobody knew. Stories were rife: everything from a paradise where no-one went hungry or sick, to a giant factory that was driven by the souls of men.

Like others of his generation, Dragon had grown up with the Wall being a constant presence. It defined where he could go and what he could do. He and his friends had been born in its shadow; they had played and fought in its shadow; they would likely die in its shadow. They could not conceive of life without the Wall.

Then it changed.

It was night. The Wall was lit up; its concrete seemed to glow against the dark sky above. Shadows moved along the walls of the nearby buildings and stretched down the alleys of the barrio. Dragon's crew was in their den, planning the night's activities, when their discussions were interrupted by a rising babble of voices. Parang - the leader of the crew - pointed at Dragon. "Go see what's happening," he ordered.

Dragon hurried to obey. He looked out of the window to see what the commotion was about, then stopped, unable to believe what he was seeing. The Wall to the west was dark. As he watched, the lights at the top of a section of the Wall went out. Then the next section went dark. And the next. Slowly, steadily, a wave of blackness consumed the Wall.

"It's the Wall," Dragon said.

They rushed from the den, forcing their way through the crowds to see for themselves this new phenomenon. By the time they reached the edge of the barrio, the entire Wall was dark: a strip of blackness stretching from east to west. The inhabitants of the barrio had gathered at the base of the Wall, staring in disbelief and awe at the sight.

Dragon looked at the crew. He wanted to step forward, to test this new boundary. But that would mean entering the Death Zone. He wondered who - if any of them - would take that step forward.