Masters of the Maze (Avram Davidson novel)
Encyclopedia
Plot summary
The Maze connects worlds and times. The secret of the Maze is known by its Masters but they decline to intervene. At various levels the Guardians thwart invasion attempts of worlds by inhabitants of other worlds. But the Chulpex, alien hive beings, try to find their way past the Guardians to attempt the colonization of a new world and an ordinary EarthmanEarthling
Earthling is a term commonly used in science fiction to identify humans as opposed to extraterrestrials. The literary effect aimed for is a distancing effect, inviting the readers to contemplate their own species as it might be seen from an external point of view...
with no training has to stop them.