American diplomat Robert Thorn (Gregory Peck) and his wife Katherine (Lee Remick) are expecting their first child while in Rome. It’s a dark and stormy night and Robert is given some very bad news. Father Spiletto (Martin Benson) tells Robert that his son was born stillborn. The good father tells Robert that another baby was born this night and the mother passed away and they can substitute this baby for his and his wife need never know that her baby died. Robert agrees.
Soon Robert is made the American ambassador to Britain and he moves Katherine and Damien (Harvey Spencer Stephens) to England. Strange things start to happen around Damien. A large black dog appears. At his birthday party his nanny hangs herself in front of everyone. The new nanny, Mrs. Baylock (Billie Whitelaw), is even creepier. A priest, Father Brennan (Patrick Troughton), appears and tries to warn the family about Damien.
When the priest is mysteriously killed a reporter, Keith Jennings (David Warner) starts investigating and contacts Robert. Keith believes that Damien is the son of the devil. Robert agrees to help Keith investigate. While the two are looking into the mysterious birth back in Rome, Damien causes Katherine to fall and miscarry.
The Omen was directed by Richard Donner who would go on to movies like Superman and Lethal Weapon but his work here is intense. There is a constant sense of foreboding and Gregory Peck is excellent as the father who realizes that his son is the anti-Christ. Several sequels would follow but none of them as good as the original.