The Omen (1976)

In Richard Donner's classic supernatural occult horror film of demonic possession that was the first part of a trilogy, followed by Damien: Omen II (1978), and The Final Conflict (1981) (aka Omen III), and a remake in 2006 - the mostly-believable story about Satanic conspiracy contained a number of cleverly-constructed set-pieces of suspense, revolving around a conspiracy that was being investigated by a well-intentioned, victimized father:

• the set-up: local priest in Italy Father Spiletto (Martin Benson) offered an orphaned infant child (whose mother had died "in the same moment") to US diplomat Robert Thorn (Gregory Peck), after his distraught wife Katherine Thorn (Lee Remick) had given birth to a stillborn child in a Rome hospital on June 6, 1966 (6/6/66) at 6:00 am: "Your wife need never know. It would be a blessing to her and to the child"

6/6/66 at 6 am

• the child was named Damien (Harvey Stephens) [Note: soon revealed to be the Devil's own son, or the Anti-Christ named Damien (Harvey Spencer Stephens) with the 666 mark of the beast - a sign in the form of a birthmark on his scalp]
• the child was celebrating his 5th birthday party (outdoors) in England (Thorn had been appointed the US Ambassador to Great Britain), when his nanny (Holly Palance) went into a trance when she saw a black Rottweiler on the grounds; she went into the mansion's top attic, tied a noose around her neck, stood out on the ledge of the window, and jumped and hung herself (and shattered the second floor glass windows with her swinging body) after calling out her final words: "Damien, look at me. I'm over here. Damien, I love you. Look at me, Damien. It's all for you"; Damien's view was shielded by his mother Katherine, but he seemed pleased - he waved at the Rottweiler (a protective Hellhound)

The Suicidal Death of Damien's Young Nanny

• the visit of Catholic priest Father Brennan (Patrick G. Troughton) to Thorn's office, warning him that he had adopted Lucifer's son (the son of the devil born of a jackal); he specified an antidote: "You must take Communion. Drink the blood of Christ and eat his flesh. Only if he is within you can you defeat the son of the devil....He's killed once. He'll kill again. He'll kill until everything that's yours is his....Only through Christ can you fight him. Accept the Lord Jesus. Drink his blood"
• the unexpected arrival of a new governess, Mrs. Baylock (Billie Whitelaw), who confidently asserted that Damien wouldn't be shy with her: "Not with me, he won't be"; in private, she told Damien: "I am here to protect thee"; she made strange assertions to the Thorns that Damien shouldn't attend a church service: "Do you really think a five-year-old will understand the goings-on of an Episcopal wedding?" - and Damien's frightful reactions and screams (and pulling of his mother's hair) as he arrived by car at the church
• the scene in which giraffes were spooked in the Windsor Safari Park and babboons instinctively recognized Damien's devilish-nature and attacked the car carrying Damien and his mother
• after severe warnings by Father Brennan to Thorn in Bishop's Park about his endangered family (Katherine was pregnant), and instructions to kill their child Damien: ("Go to the town of Megiddo in the old city of Jezreel. There, see the old man Bugenhagen. He alone can say how the child must die...Your son, Mr. Thorn. The son of the devil. He will kill the unborn child, then he will kill your wife, and when he is certain to inherit all that is yours, then, Mr. Thorn, he will kill you...With your power, he will establish his counterfeit kingdom here, receiving his power directly from Satan...He must die, Mr. Thorn"), and then in a "bizarre tragedy," the Father was impaled to death during a freak storm outside a church by a heavy steel lightning rod that was struck by lightning, broke off, sailed through the air (like a javelin throw) and skewered him into the ground
• while pregnant Katherine was having ominous fantasies described by a therapist ("She fantasizes that your child is alien and that your child is evil"), the scene of Damien maniacally pedaling his red and white tricycle and knocking his pregnant mother over the second-floor stairway railing to the menacing sound of ''Ave Satani", causing her to fall, miscarry, and suffer "a concussion and a broken humerus, and, well, some internal bleeding"; recuperating, she was able to tell her husband: "Don't let him kill me"

Tricycle Accident?

• the scene of photographer Keith Jennings (David Warner) informing Thorn of the seemingly-insane Father Brennan's grave condition before his unusual death: "The coroner's report shows that he was riddled with cancer. High on morphine most of the time. Injected himself two or three times a day...Externally, his body was normal, except for one thing on the inside of his right thigh...Three sixes. Six hundred and sixty-six..." - the same numeric configuration of the date of Damien's birth in Rome (6/6/66), and the time of a strange astronomical phenomenon five years earlier in Europe: "A comet changed its shape into a glowing star, like the star of Bethlehem 2,000 years ago" - a signal of the birth of the Antichrist, the Devil's child!; the three 6's signified the unholy Diabolical Trinity - the Devil, Antichrist and False Prophet
• while in Italy after visiting at a remote monastery in Frosinone and speaking to gravely-ill and badly-burned Father Spiletto (who was present five years earlier in the maternity ward where Damien was born that had since burned down), Thorn and Jennings were guided to an ancient Etruscan cemetery known as Cerveteri at the ruins of Cripta Sant'Angelo (50km north of Rome) to investigate Damien's origins; there, they found the remains of Damien's biological mother Maria Scianna, a jackal carcass - the jackal had impregnated the mother, and the murdered Thorn bambino-child! - "They murdered him as soon as he was born"); they were attacked by a pack of vicious black Rottweiler dogs and barely escaped
• back in the UK, the death of the heavily-sedated and recovering Katherine, after her mysterious nanny replacement, Mrs. Baylock, shoved her out of a high-floor hospital window, and she plunged through the roof of a parked ambulance below
• the discovery at Megiddo by Thorn from exorcist Carl Bugenhagen (Leo McKern) that Damien had to be killed on "hallowed ground" (a church altar preferably), using each of seven mystical daggers: "His blood must be spilled on the altar of God. This first knife is most important. It extinguishes physical life and forms the center of the cross"
• the demise of hapless photographer Keith Jennings who had just vowed to the reluctant Thorn that he would stab his evil son Damien with one of seven daggers if Thorn couldn't do it ("If you don't do it, I will"), but then he was decapitated during a freakish accident when a sheet of plate glass sliced through his neck; it flew off a truck that lost its brakes when parked on a slight incline; the vehicle gathered speed as it went out of control; the sheet of plate glass flew off the open flat-bed of the truck and sliced cleanly through Jennings' neck; it sent his spinning body-less head flying through the air; the head ended up resting on the ground where it could view itself in reflected glass
• the concluding climax of Thorn cutting off some of Damien's hair to locate the "666" marking on his scalp, fighting off Mrs. Baylock ("an apostate of Hell") and stabbing her with both a carving fork and screwdriver in the neck, and then bloodied himself, dragging his screaming son away to a nearby church altar to sacrifice him, according to Bugenhagen's instructions, with the seven mystical daggers from Megiddo (a derivative of the word "Armageddon" and the site of an archaeological dig outside Jerusalem); Thorn was shot to death by police as he raised his hand with the first dagger

• the sequence of a double-Thorn funeral at Arlington National Cemetery attended by the US President (off-screen), Robert's brother, who had adopted Damien - the devil-child stood next to him during the ceremony, and then turned back to look at the camera while smiling, as the film ended
• the epilogue (white letters on black): "Here is wisdom. Let him that hath understanding count the number of the beast: for it is the number of a man; and his number is 666. Book of Revelation Chapter 13 Verse 18"