Futuristic settings have always been a popular vehicle of science fiction writes. H.G. Wells,  Orwell,  Huxley, Bradbury. And they seem to have become a popular film vehicle as well. Most ending with either the heroes finding hope and a new and better life or the beginning of the end. They usually involve some natural or man made disaster or a combination of the two. Some envision a world we humans have resin above there more darker traits to explore the galaxy with only a few bumps along the way.

Blade Runner takes a much darker and to me at least, more probable view of the future.  A future where space colonization is in progress and has been for some time but is a commercial venture. Where slavery is  use on these colonies to perform all the hard physical work and fighting. But these are not Human Slaves but bio-engineered androids. Made to order slaves designed to perform particular tasks. Replicants they are called. Humanoids that have been genetically engineered.  The main way to detect them is with a test that measures emotional response.  A group of replicants staged a rebellion on one of the colonies a while ago, so it is now illegal for replicant to be on earth.  On top of that because they develop their own emotions over time, they have been engineered to have only a four year life span.  This emotional aspect I would surmise,  frightens humans.

The film takes place in a dystopian Los Angeles in the year 2019. Well science fiction writers tend to be a bit optimistic about technological advances. Because it has been deemed illegal for replicants to be on earth,  special police squads - know as blade runners - were formed to hunt them down and as is euphemistically referred to as retire them.  In other words kill them on sight.  Six replicants had killed 23 people on a colony and stolen a shuttle craft and landed on earth. Our hero, Rick Deckard (Harrison Ford) an ex-blade runner, is persuaded or rather black mailed by his old police captain to take on the task of hunting these six down. 

The cinematography is quite stunning and you get the feeling of how run down this version of LA is. It's really quite striking.  It's big, with buildings hundreds of feet tall but not well maintained. Brimming with people but most are just making it the best they can. The biggest building in the city is the Tyrell Corp. which makes the replicants.  A kind of cross between a pyramid and an aircraft carrier. It is owned and run by Dr. Tyrell a genics genius who has built a corporate empire on genetically engineered slaves. 

The air is poor and the sun shines yellow in the widows of  Tyrell Corp. building. It's nearly always raining though on the lower levels and the street below. Like the city has become some vast urban version of a tropical rain forest.  There are a lot of people in the street and it is nearly always dark. One thing that strikes me right off is that there are a lot of Asians, Chinese and Japanese as well as people from India etc. The man street language is "Cityspeak". Apparently a mix of Asian and Latino which Deckard says he cannot understand but it become obvious he understands more than he lets on. The police use a vehicle that can hover,  fly through the air or drive on the ground. So that they can keep an eye on the citizens. It's obvious though that a lot goes on on the street that they do not or cannot pay attention to.

There are constant passings of hovering blimp like vehicles advertising both with visuals and audio the benefits of relocating to the "Off World Colonies" for those who qualify. Mostly individuals with advanced skills and who can pass a special physical.  That for "The Good Life"  one needs to relocate to the colonies. 

The back drops of the street are unbelievably gritty. With tall old buildings, mostly uninhabited.  People dress in what can only be described as early salvation army attire. Or what you might find in a bag ladies bag. We learn fairly early on that the Tyrell Corp. employs people as private contractors. As two of the replicants pay a visit to one of them. An old Chinese gentleman who makes eyes to be used in them in his own cryogenic lab. We also learn that this bio-genetic technology has made it to the street as there are those who make bio-engineered animals such as snakes and fish and even ostriches.  The Tyrell Corp. slogan "More Human Than Human" is uttered by Dr. Tyrell and by Rachelle, a experimental replicant of Nexis type 6. The most advanced. Though she is not originally aware that she is, which puzzles Deckard.  Deckard is first set to check out the this new model replicant with the test.  Dr. Tyrell has him perform it on Rachelle and she asks if Deckard has ever "Retired" a human by mistake. He says no.  It takes over 100 questions but Deckard figures out she is a replicant and Dr. Tyrell tells him that the difference is that she was given childhood memories and is the first replicant to have them.

Deckard returns to his apartment, rather shabby on the inside but also with appropriate high tech for his old profession. He finds Rachelle there and she says "You think I'm a replicant." at which point he points out to her that she is and that here memories were implanted. He also begins to have some feelings of compassion for her.  He eventually tracks down one of the six replicants and after the usual chase blows her away. You can tell he is emotionally repulsed by this and it is the first real hint of why he quit originally as a blade runner.  He then comes across a second replicant but is nearly killed himself by it but is saved by Rachelle who shots the replicant herself with his weapon.  Providing the evidence that replicants are just as capable of the same emotional response as humans.   There are now only two left and it is made clear why they had come. To see Dr. Tyrell. To get him to extend their lives beyond the fours years programmed into them. They meet J.S. Sebastian. A geeky kind of a person who does genetic design work for Dr. Tyrell and almost worships the man.  Sebastian lives by himself - the only one in a big rather decrepit and aging old hotel of 1930s vintage.  Roy Batty and the other remaining replicant convince Sebastian to take Roy to see Dr. Tyrell using Sebastian's long running game of chess as the reason to want to see him.  After arriving at Dr. Tyrell's plush apartment in the Tyrell building, the deception is reviled as is the motive for the visit. To find out why the replicants cannot get a longer live span.
When Roy finds the Dr. Tyrell - the one who designed and built him - really just thinks of him as some bio-mechanical  device, Roy is enraged and brutally kills Dr. Tyrell. It is inferred that Sebastian, who witnessed the whole gruesome scene, meets a similar fate.

Finally Deckard comes to the last replicant. Roy Batty, a strong intelligent Nexis 6. Much stronger than Deckard and corners him on the roof of big old hotel building that J.S. Sebastian lived in. Deckard attempts to escape by jumping to another building but misses and hangs by one hand.  Deckard's hand slips but Batty grabs it just in time and hauls him up to the roof. Then sits crumpled, his last bit of life fading fast but just before dying says. 

"I've seen things...seen things you little people wouldn't believe... Attack ships on fire off the shoulder of Orion bright as magnesium... I rode on the back decks of a blinker and watched c-beams glitter in the dark near the Tanhauser Gate.....all those moments... they'll be gone."

And Deckard sees and we see the point and pointlessness of what has transpired. That they are not mere machines and useful objects to be discarded at will.  And the take away from this film ? Not much really. You will not get any warm fuzzy feelings from it.   What you see is a future where humanity has progressed technologically but has slipped back quite a bit morally and ethically in certain areas. A future that does not end in disaster or bright new Utopian beginnings but continues on a bit darker and a bit grittier than before.

As for Deckard and Rachelle, they admit their love for each other and leave the city. Does she last beyond the four years ? We do not know and neither does our hero.  She was after all an experimental model.  Not for general use. And as officer Gaff (Edward James Olmos) says at the end.

"It's too bad, she don't last, eh! But who does."