At the beginning of "Ninja III: The Domination," a "top scientist," taking some recreation on the links, slices a ball into the rough. When his bodyguards go to retrieve it, they are met by a Ninja assassin who crushes the golf ball in his fist and emphatically dispatches them. As well as the scientist, whose head is cleft as neatly as a cantaloupe.

Never has the case for accurate irons been made so compellingly. Law enforcement gives chase, but the assassin puts the kibosh on 21 policemen (I may have missed one or two) until, riddled with an amount of lead likely in excess of his body weight, he perishes.

The scientist is never identified, nor are we told why anyone would want to kill him. That's the fun of exploitation movies like "Ninja III" -- the transparent way they create occasions for mayhem. Bones are made without making any bones about it.

But "Ninja III" quickly falls off track. The best violent movies are relentless -- in "Sudden Impact," for example, Dirty Harry can't even buy a cup of coffee without tripping into a shootout. Similarly, Walter Hill never took the pressure off in his classic "The Warriors"; and he invested it with a look so luscious and imaginative that it seemed like more than the martial arts movie it was.

"Ninja III," by contrast, employs a strategy of random excess. The soul of the dead Ninja enters the last person to see him before he dies, Christine (Lucinda Dickey), a telephone lineman by day and an aerobics instructor by night. She lapses in and out of a murderous trance, pursuing revenge against the surviving policemen on the Ninja's behalf. In her conscious life, she falls in love with one of the cops, Officer Secord (Jordan Bennett); she pours V-8 juice on herself, and he licks it off (was kinky sex ever so low-calorie?) When Secord realizes that she's possessed, he hires a Japanese shaman to drive the Ninja from her psyche, but to no avail -- as everyone knows, "Only a Ninja can destroy a Ninja."

Dickey is tawny and coiffed to look like Jennifer Beals; Bennett is a dead ringer for Michael Nouri. The movie is fat with scenes of Dickey, lacquered with sweat, jogging mightily in leotards, leg warmers and torn T-shirts to an electronic score ("Is your sex life fiction because you live in the kitchen?" screams a typical lyric). "Ninja III" is a sort of "Samurai Flashdance Meets the Exorcist."

This reckless stew of genres flattens "Ninja III," which is at its best during its action sequences, choreographed with flair by director Sam Firstenberg. Victims aren't merely hit in this movie -- they're hurtled airborne across city streets, blown into dumpsters, propelled through tombstones. A Ninja can jump a 12-foot fence from a standing start (take that, Edwin Moses!), drive a fist through the top of an automobile, or crush a billiard ball with his bare hand. When a Ninja wants to come into a room, he goes to the floor below and, using his head as a battering ram, jumps through the ceiling. And you thought only Cary Grant knew how to make an entrance.