Alexander is a young man with a marvelous talent to program computers. Gradually, he enhances his own personal computer to the point where it can take over the world for him, and then pushes matters a little too far and loses all.
This is a story in the classic Greek form of hubris/nemesis, where some mortal develops overweening pride (hubris) and is brought low by the gods (nemesis). There’s really nothing interesting about it—the idea of somebody programming a computer to take over the world is a bit wild-eyed and cliched and not terribly interesting in its execution. The nicest thing about this story is that it doesn’t last very long.