At first glance the story is simply about Locke. He has no family name; when asked "Locke what?" he replies "Just Locke." His genesis is before the "Cosmic Year" calendar used in the story. Although there are rumors that the author has an origin in mind for Locke, it is still a mystery to readers as well as to the other characters in the story. All of the stories deal either directly with Locke or with actions only slightly removed from him. The primary plot deals with Locke's involvement in struggles against evil of one sort or another—either human or quasi-supernatural. Frequently Locke is drawn into events that are happening around him. Either he stumbles onto a situation that his heart will not let him ignore, or one of the other players begs him to join their cause. Sometimes he relents and joins their cause; sometimes he ends up opposing them.
As the story slowly grows around the reader (and there is a lot of story!) he finds that it is a chronology of human history in the future. Locke is the medium through which we see humanity as it evolves, travels, discovers, explores, colonizes, conquers, fights, and destroys. He is the eye on humanity. He is also the will to do right.