Jonnie, a human from a remarkably primitive tribe living in a valley in Colorado, goes exploring in the thousand-year-old ruins of civilization from before an alien invasion. In a hilarious coincidence, Terl, a greedy alien security officer, is having a holiday in those same ruins, and has a scheme to collect some gold and become wealthy with the help of human slaves. After nearly killing Jonnie through his staggering incompetence, Terl brings his pet human back to the mining base he works at and sets about training him.
After a few futile escape attempts, Jonnie is introduced to learning machines that let him quickly grasp the aliens' language and technology. There's a pointless sequence where Jonnie's debut on a tractor is sabotaged by another alien for giggles, but Terl eventually blackmails his superior into going along with his plan to acquire human workers. Oh, and Jonnie's vapid girlfriend gets captured too.
Terl takes Jonnie to Scotland where the plucky little human is able to bend hundreds of strangers to his will. While ostensibly mining Terl's gold for him, the barely-supervised humans scurry about collecting ancient weapons for use against the aliens dominating Earth. Then, just when Terl thinks they've gathered his retirement fund and is about to kill them off to cover his tracks, the humans strike. They teleport "planet-buster" bombs to the alien homeworld and launch a coordinated attack on the alien bases scattered across Earth, taking them completely by surprise. As a last act of spite Terl launches a drone bomber that could gas the remnants of humanity out of existence, but Jonnie manages to board and sabotage it, just barely surviving the ordeal.
Putting it like that, Battlefield Earth doesn't sound so bad, does it? A nice little story that ends on a triumphant, if somewhat uncertain note - sure, the humans have pantsed the aliens and retaken Earth, but they're still not sure if their attack on the alien homeworld was successful or not. But all in all, not a bad place for the book to end.
Except it doesn't. We've had our "climax," but there's no denouement or anything. Instead we get 632 more pages of stuff happening afterward. Next Part has Jonnie recovering from his injuries, and then we get what Hubbard passes as political intrigue, and then there's the excitement of Jonnie trying to master Psychlo mathematics. There's a dogfight later, and a few explosions, and cannibals, but nothing to live up to the "liberate the planet" plot.
I think I've said this already, but my theory is that Hubbard realized he couldn't Mission Earth this one, that few people would read the four hundred and fifty pages covered so far and want to pay for more of the Battlefield Earth saga.
I mean, we have Jonnie, who is about as endearing as a brick and unstoppable to the point of boredom, and a bunch of Scottish stereotypes, and some supposedly nefarious alien villains who lack the foresight and common sense to run a McDonald's. The Psychlos are huge, hulking monsters that are tossed around by Jonnie in close combat with little effort. The aliens possess devastating weapons that are handily defeated by bazookas or Jonnie and a wrench. The Psychlo empire is an unstoppable military juggernaut that doesn't even make an appearance. The actual battle for Earth, hyped for hundreds of pages, is over in a flash and completely one-sided. I think the book spent more time covering the humans' search for gold or uranium than it did on the liberation of the planet.
Oh, almost forgot Chrissie. Wonder why.
And the plot holes! Why is the invulnerable bomber drone given a stealth suite but not the Pscyhlo fighters? How are the Psychlos able to launch surprise teleportation attacks if living creatures require a "slow firing" to arrive safely and still comes out shaken and disoriented? How can an empire that spans universes function if its communications system is correspondence teleported around?
And then there's the science. Radiation you can just wash off. Alien air that explodes in the presence of a single isotope of uranium. Teleportation engines that propel aircraft forward instead of actually teleporting them to their destination. Invincible armor that sometimes isn't. Nuke-proof aircraft. The only technology I accept without question is the Psychlos' blaster weapons, and that's because Hubbard hasn't tried to explain how they work.
The point I'm trying to make is that this isn't a good book. And it's not over. We're not even halfway done with it.