Robert Thorn

The Thorns are soon joined by a new nanny, Mrs. Baylock, who is a servant of Satan. Soon after she arrives, Katherine's feelings toward Damien changes. In the novel, Katherine complains to Robert that Damien is more comfortable with Mrs. Baylock than with her.[4]

Later, Katherine wants to take Damien to a church wedding. Baylock strongly opposes and does everything to change Katherine's mind. Ultimately Damien is taken to the church, but attacks his mother out of fear. Although Katherine does not make much of it and is convinced he had a bad day, her mind later changes.[4]

The next day when she takes him to the zoo, the animals react to Damien's presence in a violent way. This causes serious emotional damage to Katherine later that night.[4] She cries to Robert that she needs a doctor, but refuses to tell him what exactly her problems were. After seeing a doctor, she starts to get annoyed by Damien and cannot stand his presence.

Thorn gets an unexpected visit from a priest, Father Brennan (Father Tasson in the novel) the day following the first nanny's death. He tries to warn Thorn about his son's origins,<ref name=cinelinx>hoping to be forgiven by Christ by doing so. Naturally Thorn does not take it seriously and asks him to leave. The priest however persists and days later requests to meet with him at the Bishops Park. He warns Robert that if he does not come, his wife may be in danger.[4]

When Robert meets him, Brennan tells him that Katherine is pregnant and the child will die while it is in the womb. Damien will kill first the child, then Katherine and when he is certain that all of Thorn's properties will be his, he'll kill Robert as well. Brennan tells him to meet Bugenhagen in Israel who will tell him how to kill Damien.

Robert leaves with anger and then Brennan dies in a freak accident. The next day Robert learns Katherine is indeed pregnant and wants an abortion, to which he opposes. Robert is told by an unknown caller to check the newspaper; when he does he sees the news regarding the priest's death. Robert now starts to suspect that something is indeed wrong.

Keith Jennings (Huber Jennings in the novel) had attended Damien's fifth birthday party. An eyewitness to the nanny's suicide, he becomes very interested in the Thorns. He starts to follow Robert and take photos of people associated with him. The day following the nanny's death, Robert mistakenly breaks Jennings’s camera in front of the embassy. That same day when Brennan leaves the embassy Jennings takes his photo and sees an unusual mark in the picture. Days later he sees the priest with Thorn again and once again the photo he takes contains the same mark. When Jennings sees the priest dead via a pole passing through his body, he is convinced that the marks he saw in the photos were an omen that he was going to die. A similar mark is seen on the photos he took of Damien's first nanny on his birthday before her death.

After showing the photos to Robert, Jennings gives him additional information about Brennan. Brennan had cancer and knew he was dying.[4] He had a birthmark on his right thigh. The birthmark describes a sequence of sixes (known as 666). Later they go to Brennan's place which is fully covered with pages of the Bible and 47 crosses. Jennings had found a diary that contained all the information Brennan had gathered by stalking Robert. The last entry said he was supposed to meet Thorn at the Bishops Park the day he died. Jennings shows Thorn a few paper clippings from five years ago. One is Damien's birth announcement; another is about an unusual phenomenon; an unusual star, much likes the Star of Bethlehem that appeared five years before.

Trying to figure out the meaning of the birthmark, Jennings asks if Robert is his son was born June the 6th, 6 AM. Robert then confesses for the first time that his son is dead and he has no idea whose son Damien is. Jennings wants to help him find out more about Damien but Thorn refuses saying it is his personal matter. Jennings then shows his photo accidentally taken by himself on the mirror which shows the similar mark; implying he will soon die as well.[4]

Robert travels to Rome with Jennings and goes to the hospital where Damien was born; only to find out the old hospital burned down five years ago, killing many staff and destroying records.[3] A nun helps Thorn by telling him that Father Spiletto is at a monastery in Subiaco. Thorn and Jennings find Spiletto badly burnt. A monk informs them that he does not speak or move; only his right hand moves with which he confessed that he had abandoned Christ. Thorn asks him to confess to him as well and tell him the whereabouts of Damien's real mother. Spiletto spells 'Cervet' and the monk tells them that Cerveteri is an ancient and abandoned Etruscan graveyard.

Thorn and Jennings go there and find the graves of Jackal, Maria Avedici Santoya and a child, whose skull was smashed to death. Thorn realizes his real son was murdered and Damien is not human. They are then attacked by Rottweiler dogs and barely escape the cemetery.[3]

Soon Thorn and Jennings return to their hotel from where Thorn calls Katherine to leave London and come to him as soon as possible.[3] Jennings tells him to try to remember all that Brennan told him at the Bishops Park while he goes to find out about the town of Megiddo.[4] Thorn soon learns Katherine is dead and has the urge to kill Damien. By the time Jennings returns he remembered all the things Brennan told him.

The next day they go to Megiddo, Israel to meet Bugenhagen. Bugenhagen gives him "Seven Daggers of Megiddo", the only tool that can kill Damien. He explains Damien must be killed on Hallowed Ground. So that Robert is convinced, he tells him to find a 666 birthmark on Damien's body. Deeply disturbed by the idea of killing a child, Thorn throws away the daggers soon after leaving Bugenhagen. Jennings is decapitated while trying to pick them up. Finally convinced of evil forces surrounding him and feeling responsible for Jennings's death, Thorn takes the daggers and flies to London.[3]