This cult classic opens graveside. An old man's wife is being interred. Aliens are lurking in a flying saucer, waiting to revive the corpse. You see, humans have been ignoring these aliens and their flying saucers, and the aliens' feelings are hurt. Also they want to warn us to stop our arms race. To really get our attention, they are going to bring corpses to life (=plan 9). That'll show 'em!
This movie is the reason Attack of the Killer Tomatoes richly earned the two stars I awarded it. Frankly, Plan 9 makes Killer Tomatoes look like The Shining. There is no element of Plan 9 that is well done. Sets? Brutally cheap and thrown-together. Acting? Horrific. Dialogue? Don't make me laugh. Continuity? None. Plot? Ludicrous. Scariness quotient? Zero. Editing? What editing? Plan 9 from Outer Space? Awesomely bad.