Doctor is a seer, like Hieronymous, but when the astrologer quizzes the Doctor, it becomes clear that the Doctor does not believe in any of it. Federico orders the Doctor to be executed as a spy. Meanwhile, Sarah is brought before a priest and told that she is the foretold sacrifice to Demnos, the Roman god of moonlight and solstice. In the palace courtyard, the Doctor is led to the executioner. Before the executioner's sword lands, the Doctor unfurls his scarf and hooks it around the executioner's ankle, throwing him off balance. The Doctor escapes and finds his way into catacombs beneath the city. The guards, fearing the Brethren of Demnos who reside there, stop their pursuit. Inside, Sarah is laid out on an altar. A purple-robed figure is about to stab her when the Doctor snatches Sarah away, just as the fragment appears in the chamber, suffusing it with a red glow and providing a distraction for the two to escape. Giuliano examines the body of a guard who was killed earlier by the fragment, and while he does not know the cause of the guard's death, he dismisses ideas that it was some kind of fire demon. The Doctor and Sarah are found by palace guards. In the temple, the Helix manifests itself as a pillar of red light and tells the purple-robed figure that he will be given undreamed-of powers to carry out its will on Earth and become the planet's supreme ruler. After the Helix vanishes, the figure removes his mask, revealing the face of Hieronymous. The guards take the Doctor and Sarah to Giuliano, who shows him the dead guard's body and tells the Doctor of fears that if Federico rules San Martino, all knowledge and learning will be suppressed. Elsewhere, Federico discovers that Giuliano has invited several nobles to San Martino to celebrate his succession to the Dukedom. Angered, Federico demands Hieronymous make up a new horoscope and poison Giuliano before the next evening. The Doctor deduces that the Helix chose San Martino because the Brethren provided a ready-made power base. The Doctor asserts that the 15th century was the transition between the Dark Ages and the dawn of the Renaissance – the Helix could gain control of the Earth now through a new religion. The Doctor tells Giuliano the temple must be destroyed. They go to the temple, and the Doctor enters the