AFr Francis and Joseph take refuge in the church from the sandstorm and from the Turkana who are trying to kill Joseph, believing him to be possessed by the demon, while Merrin goes in search of Sarah. Although he can't find Sarah, he finds her room to be covered with blood, swarming with maggots and flies, and finds an icon of Pazuzu. He also notices a photo of Sarah and her husband. Putting two and two together, Merrin concludes that Sarah accompanied her husband when he first entered the church and that it is her in which the demon has taken residence. Back in the church, Fr Francis attempts to exorcise Joseph but is killed by the demon in Sarah's body. Meanwhile, the British soldiers and the Turkana warriors have begun attacking each other. Racing to get back to Joseph and Fr Francis, Merrin loses the icon in the sand. When he finally gets inside the church, he sees that Fr Francis is missing. Realizing that he is the last hope, Merrin picks up Fr Francis' crucifix, alb, Rituale Romanum, and vial of holy water and begs God to forgive his doubt. Then he goes after the demon-possessed Sarah. They pursue each other through the halls and tunnels of the netherchurch. At one point, Sarah threatens to break Joseph's neck; at another point, Merrin tries again to exorcise the demon from Sarah's body. Finally, Merrin hands Joseph the Rituale Romanum, shows him where to read, and they say the exorcism together. This time he is successful, the demon leaves Sarah's body, but she falls battered and bleeding to the ground and dies in Merrin's arms. Merrin and Joseph dig themselves out of the church to find that the British soldiers and Turkana warriors have annihilated each other. In the final scene, Merrin meets again with Semelier this time in Rome. He returns the replica of the demon, saying that he could not find what they were looking for. "But you found something, didn't you?" Semelier asks. Merrin walks away without comment. "Au revoir, Mr Merrin," Semelier says. Merrin replies, "It's Father Merrin."
AThe opening scenes show a priest stumbling across a battlefield in which thousands of men have been killed and thousands more crucified upside-down. From their clothing and weapons, it appears that these are the soldiers (as it is later explained to Fr Merrin) who were sent by the Roman Emperor to track down the Evil and destroy it but who were themselves driven mad by the Evil so that they turned on each other and slaughtered themselves. It is a foreshadowing of what is about to happen in this movie when the British soldiers and the Turkana warriors clash.