Imagine a Philip Marlowe-like detective in the Los Angeles of the year 2019. Imagine him trying to track down four escaped androids who are not only murderous and superhuman but superandroid—they have begun to develop emotions. Good. Now you have enjoyed the best part of this movie, its concept, which comes from the Philip K. Dick novel Do Androids Dream of Electric Sheep? In execution, by director Ridley (Alien) Scott, this is a slothful movie, dim both literally and figuratively. Harrison Ford plays the cop assigned to hunt down the androids (why such cops are called "blade runners" is never explained in the movie). Ford is routinely proficient and colorless. Rutger Hauer, as the most advanced android, is suitably inhuman. And Sean Young, in her first major role, plays a heroine android who makes Ford fall in love with her and begin to question his lifelong fixation on "terminating" her kind. They all plod along while sometimes dazzling, sometimes boring special effects whiz by and Ford's climactic confrontation with Hauer approaches. Instead of tension building, though, things are grinding to a halt, including Hauer's gears. Can Ford issue a total recall on Hauer's model? Will Young's transmission stand up to the heat of her couplings with Ford? If this is Los Angeles, why is all the space-age traffic moving so freely? Better you should go down to your local foreign car garage and watch them repair a Porsche, if you want to see something really exotic. (R)