The Invaders Plan : MISSION EARTH VOLUME I by L. Ron Hubbard (Bridge: $18.95; 559 pp.)

In the ‘30s and ‘40s, before founding the Church of Scientology, the late Lafayette Ron Hubbard was a popular and prolific science-fiction writer. His 1948 novel “Final Blackout” among other works is considered by many a classic of the genre. Recently, Hubbard returned to the field with “Battlefield Earth: A Saga of the Year 3000,” a lengthy epic of heroic Earthmen’s resistance to alien invaders.

Alien invasion is once again on the agenda in “The Invaders Plan,” Volume 1 of a proposed “Mission Earth” decalogy (which means, a footnote on the dust jacket too thoughtfully informs us, “a group of ten volumes”). This time we’re treated to the viewpoint of the would-be invaders, very human humanoids of the intergalactic Voltar Confederacy. Earth’s impending self-destruction through pollution and nuclear war threatens to throw off their age-old “Invasion Timetable,” which causes great consternation until the head of the Gestapo-like Apparatus offers to mount a secret mission to save “Blito-P3”--Earth--from its inhabitants.

The narrative’s first person, Apparatus functionary Soltan Gris, is assigned to guide combat engineer Jettero Heller, the real hero of the piece, through “Mission Earth.” The problem is that his superior has ordered him to make sure the rescue scheme fails.

Though Heller starts out a prisoner, he escapes Gris’ control the instant he’s released from his cell to begin preparing for the mission, and Gris never catches up. But that’s not surprising, since “Jet” Heller is a combination of Tom Brown, Albert Einstein, and the cartoon character He-Man, who throws a tournament to make a fellow officer look good to his sweetie, absorbs one-hour instruction tapes in 30 seconds, and twirls 100-pound exercise bags on one robust finger. Gris, on the other hand, is a boob, who hasn’t even mastered elementary graft, and is oblivious to the ominous fact that Heller and his paramour fortuitously hail from the same world, which has a tradition of resistance to Voltar and whose legends claim that one of its rebellious noblemen long ago established a colony on--wait for it--Earth.

Eventually we learn that the Apparatus boss plans to use Earthly heroin and speed to undermine the Confederacy’s ruling aristocracy and enable him to become Emperor. Why he should want to derail salvation of the planet that supplies those drugs is as mysterious as why such a technologically advanced civilization can’t synthesize them.

Parts of “The Invaders Plan” read as if poorly translated from the Japanese. “The blastgun barrel was into my stomach with violence!” goes one entire paragraph, characteristically substituting typographical stridence for the crisp prose and well-visualized action so conspicuously absent from the book.

Satiric intent cannot make up for weakness of prose, pace, characterization or lack of a credible plot--the more so since it’s unclear what this book and the rest of the decalogy are intended to satirize. Bloated bureaucracy, perhaps--certainly an original target. The initials of Gris’ employer, the Coordinated Information Apparatus, may provide a clue.

Satire can work as scalpel or as ax. Whoever its intended victims are, “The Invaders Plan” proves a fluffy feather pillow, wielded blindly.