He powered it on and the screen lit in a hesitant green. The generator hummed faintly, as if waking from a long dream. Mateo expected a manual, some arcane menu of numbers; instead a single prompt blinked: "Enter purpose." He laughed at the prompt's innocence and typed "help."

One morning a city inspector knocked. Complaints had been filed about unauthorized access at municipal buildings and private businesses. Mateo watched the inspector on his phone as she clicked through surveillance footage — faces unaware in the glow of fluorescent lights, a figure with a ragged coat and a nervous gait. Mateo felt exposed as easily as any weak lock. He could have lied and thrown away the generator, but the truth stuck in his throat like a key.

The machine's response was a string of numbers that unlocked nothing in the locksmith’s shop. Later, when he tested it on his own apartment's old digital lock, the keypad accepted one of the codes and the door clicked open. Mateo froze. The generator had no right to be this precise.

On the walk out, a security light blinked to life. Mateo's palms sweated. He realized the generator had given them entry without permission. The exhilaration of rescue curdled into guilt. Lian's relief was sincere; Mateo's unease was not.

The device sat under a dusty sheet on the workbench, its black plastic case scratched from a dozen moves. Mateo had been given it as payment after a night of helping an old locksmith clear out his shop: a ZKTeco keycode generator, a compact rectangle of faded buttons and a small LCD that blinked like a sleeping eye. He didn't know much about access control systems — only that places trusted these boxes to whisper secrets that opened doors.