The opening sequence in the movie begins right after the first OMEN movie, with a religious scholar uncovering a mosaic that depicts the antichrist--and it clearly has Damien Thorne's face. But before he can warn anyone he and an archeologist are buried alive when the temple crashes down upon them. Then, we go to seven years later and are introduced to a teenaged Damien. He is now living with his father's brother (William Holden), who has a son his own age. In fact, they both go to the same military school. Yet Damien doesn't know he's the son of Satan at first and seems adverse to doing evil things. There's a news reporter who believes Damien is the son of the devil who is dispatched by ravens. In the first movie it was dogs--now it's evil birds. And we discover he has secret supporters, like the vice-president of his uncle's company (Robert Foxworth), his military school teacher (Lance Henricksen) and even his adoptive mother (Lee Grant). This is all tested when he has the choice to kill his step-brother or not.
This is what a sequel is supposed to be, different from the first and continuing the story...