"Johnny Mnemonic" is a science fiction short story by William Gibson that was published in 1981. It is set in a dystopian future where information is a valuable commodity. The protagonist, Johnny, is a data courier who has a cybernetic implant that allows him to store sensitive information in his brain, but this also puts him at risk from various factions seeking to retrieve the data. In the story, Johnny's mission goes awry when he discovers that the information he carries could endanger his life. He must navigate a dangerous world filled with mercenaries and corporate interests while trying to recover his memories and find a way to safely deliver the data. The narrative explores themes of technology, identity, and the consequences of a hyper-connected society.