Richard Matheson's novel I Am Legend had been filmed in 1964 as The Last Man On Earth starring Vincent Price.

Shot in Rome by directors Ubaldo Ragona and Sidney Salkow, the film - while certainly effective and chilling on its own terms - was not entirely successful at the time.

Nevertheless in 1971, Boris Segal decided to give the apocalyptic-undead premise another cinematic shot, this time with The Omega Man...a cult classic with a depressing look at the fate of mankind.

Aided by Ron Grainer's beautiful and jaunty score, reminiscent of Italian movies of the time, Omega Man is great fun. The impeccable Charlton Heston, who was now becoming a regular in the science fiction and action genres, was cast in the lead.

At first glance...it would appear that Colonel Robert Neville (Charlton Heston), a scientist, is the only living person on the planet. A catastrophic biological war involving the Soviet Union and China has decimated the Earth's population.

Driving around the deserted streets of Los Angeles, Neville is free to take anything he wants from the various shops along the way.

When his vehicle breaks down, he simply goes into a showroom and chooses another one. The place is littered with desiccated corpses - but Neville is immune to such scenes.

It's a lonely existence that he's used to by now. But there are some unfortunate side effects. Occasionally, Neville "hears" payphones ringing...and sometimes he sees folks who may or may not be holed up in the numerous abandoned buildings downtown. Is it all in his head?

To relieve the boredom, he periodically goes to a theater to watch the film Woodstock, "a great show...held over for a third straight year," as he puts it. He's seen it so many times, he can mouth all the dialogue.

Leaving the movie house, Neville has the sudden realization that nightfall is near. "My God, it's almost dark...they'll be waking up soon!"

He races towards his apartment building but it's too late. "They" are the "Family," a cult-like group of albinos – latter stage survivors of the plague – who are intent on killing Neville.

They perceive him to be an evil and destructive enemy...and all that is representative of their undead plight. Light is the Family's weakness and the reason they do not come out during the daytime.

Several of them pounce on Neville and try to set his car on fire. He makes it up to his pad, where his only real company is a bust of Julius Caesar that he pretends to play Chess with. He needs something to distract himself from the Family...who constantly taunt him in the evenings from the street below.

The Family are led by a charismatic leader (and, in the Old Order, a former TV commentator) named Jonathan Matthius (Anthony Zerbe), who is furious that Neville has killed three of his followers.

He tells his trusted aide Zachary (Lincoln Kilpatrick) that Neville must be eliminated because he has "nothing to live for but his memories...nothing to live with but his gadgets, his cars, guns, gimmicks."

There is more than a hint of resentment - because Neville has thus far avoided the plague after he successfully injected himself with a test vaccine.

The Family spends time gutting museums, libraries and anything that represents the civilized past...throwing books and artwork into bonfires is their idea of fun.

Although they are adverse to technology, which the group blames for the world's destruction, they are able to use a catapult to send fireballs up towards Neville's apartment. Neville responds with firepower, injuring and killing even more.

The next morning, Neville roams the streets looking for the location where the Family is holed up. While in a department store, he encounters a black woman (played by Rosalind Cash) who appears to be normal. She runs away and Neville is unable to speak or catch up to her.

Later, Neville is captured by the Family in the wine cellar of a bar. He is taken to Matthias, who calls him a "refuge of the past." Denying that there is any kind of cure for the plague, Matthias believes that Neville is in fact part of the "dead."

In a scene reminiscent of Beneath the Planet of the Apes, members of the Family remove their sunglasses to reveal their white and dilated eyes...side effects of the plague that has made them the "chosen" people.

Neville is sentenced to die and as he is about to be burned alive in the middle of a stadium, he is rescued by Dutch (Paul Koslo) and Lisa, the woman from the department store. They escape on motor bikes and head towards a hideout in the countryside.

Neville is amazed to see healthy-looking children. Dutch knows of Neville's work in science. He tells him that there is no explanation for the fact that they have (for the most part) avoided obvious effects of the plague so far...the "blindness in light, albinism, psychotic illusions and occasional stages of torpor" that has afflicted Matthias and his gang.

One who hasn't been so lucky is Lisa's brother Richie (Eric Laneuville). The plague has advanced in him and his hair and eyes are turning. Neville reveals that he is immune to the plague and agrees to try and help the boy.

Dutch and Lisa take Richie to Neville's apartment and the boy is injected with the vaccine. Neville, who has not been with a woman in several years, becomes intimate with Lisa. But their kiss is cut short by the noise of an intruder.

The Family is at it again, determined to kill Neville. Zachary, carrying a spear and having gotten hold of a handgun, climbs up the side of the building.

As he is about to enter Neville's apartment, Neville shoots him and Zachary falls to his death...impaled on the iron gate below.

Neville believes he can create a serum from the antibodies in his blood. He draws blood and injects some of it into Richie. It works. Richie is cured and can be yet another source for a serum.

Lisa is thrilled. She and Neville plan to take the children and Dutch up into the mountains and away from the city and the Family. Lisa leaves Neville to go on one final "shopping" spree to prepare for the trip.

Richie's outlook is more ambiguous. He feels that Neville should share the serum with the Family to help them become healthy again. Neville refuses...helping them would mean staying in the city for months. And besides, the family is a bunch of "homicidal maniacs."

At the beginning of the plague, Lisa and Richie spent time with the Family until it became clear that they were not as sick as the others. Richie reveals to Neville that the sanctuary of the Family is located at the old court building in the Civic Center.

Neville decides to leave them alone there, knowing that they will die eventually. But Richie is naïve and goes to see the Family himself to tell them that there is a cure. He is killed for his trouble.

Neville finds a note from Richie indicating where he went and heads for the Civic Center, where he sees the boy's body.

And poor Lisa...perhaps out shopping much too long, has turned into a member of the Family. The plague has advanced in her...suddenly and without warning.

Using Lisa as bait, Matthias once again seizes Neville, this time in his home. Neville is forced to watch as members of the Family destroy his personal belongings.

But Neville manages to free himself and he takes Lisa, who is confused and not completely under Matthias's control, downstairs and outside.

Matthias watches from the balcony above. He picks up the spear left by Zachary and impales Neville, who then falls into a water fountain.

The next morning, Dutch and the kids find Lisa and Neville, who is dying from his wound. Dutch manages to get the serum from Neville and, realizing there is nothing he can do for his friend, he abandons him and loads Lisa and the children into his jeep.

Neville dies, Christ-like, in the fountain. Because of his serum, there is hope for Lisa and the rest of civilization...

From a critical perspective - and in spite of his Academy Award for Ben-Hur - Charlton Heston has always been somewhat underrated as an actor. Perhaps some critics believe it doesn't take much ability to star in the numerous 'Bible action' epics in which Heston excelled at.

But indeed, it takes a very solid actor - with a pragmatic approach to his craft and aided by a conventional style - to make a part such as Neville believable and sympathetic.

And while it's sheer conjecture, nevertheless...having already made his career mark, it must have been terribly difficult for Heston to resist the temptation to sleepwalk through this new science fiction phase of his. But it's clear he did not - and instead treated each film and its script as a challenge to be met, a life statement to be made, or simply fun to be had. Witness the poignant catalogue therein...

Heston was equally good in both Planet of the Apes (1968) and Beneath the Planet of the Apes (1970)...and in Soylent Green, released in 1973 and which has an equally grim vision of the future.

In his later years, Heston waged a war of a different kind. In 2002, he revealed to the world that he was personally battling Altzheimer's Disease. He passed away on April 5, 2008.

Screenwriter John William Corrington and his wife Joyce Cooper Corrington, perhaps influenced by the latter's Ph.D. in chemistry, changed the premise of Richard Matheson's novella from that of vampires to germ warfare. Interestingly, the duo also decided to make Neville's love interest a black woman, adding a racial dimension to the script.

Based on their work on Omega Man, they were hired two years later to write the screenplay for Battle of the Planet of the Apes, the final film of that franchise.

Composer Ron Grainer had written the music for the classic 1967 Sidney Poitier film To Sir With Love and would next contribute a score to the horror genre with the less successful The Devil Within Her AKA I Don't Want To Be Born (1975).

The Omega Man would be the second feature for Rosalind Cash, who had a bit part in the 1971 thriller Klute. Throughout her career, she worked on many television and film projects, as well as the stage. Cash passed away from cancer in 1996 at the age of 57.

As for the director...tragically, Boris Segal (actress Katy Segal's father) was killed on the set of the 1982 Made-for-Television film World War III from severe injuries caused by the rotor blade of a helicopter.