A scientist (whose name we are never told) develops an ultra-high power
microscope and makes a startling discovery. There really are worlds within
worlds. Within the atoms he observes an entire world, with people in it. He
speculates that our world may in fact be such a world contained within another
infinitely vaster world, and that there may be an infinite numbers of worlds
within worlds within worlds.
Within this microscopic world he sees a girl. And he becomes obsessed by her.
Somehow he must find a way to enter this microscopic world. He finds a way to
do just that. In the process he finds that he may be able to save not just this
miniature world but also our own world.