In McKiernan's story, a Warrow (Hobbit) named Tuck Underbank (Frodo) embarks on a quest to defeat an ultimate evil, Mordu (Sauron) who dwells in the evil land of Gron (Mordor). Along the way he encounters a dwarf called Brega (Gimli), an elf named Gildor(Legolas), a human warrior (Aragorn), etc, etc, etc...The Tolkien plagiarism's go on and on.
He even includes a scene where some of the main characters have to pass through an abandoned Dwarf city called Kraggen-Cor (Moria). The city is abandoned because some terrible monster Ghath (Balrog) drove all of the dwarfs out long ago. The only way into the subterranean city is through some magical doors that they have some difficulty getting open. While waiting at the doors, a monstrous squid/octopus-like creature attacks them. And yes, there is even a battle with the Ghath in the dwarfin city on a narrow bridge over a bottomless cavern.