Helix, which begins infusing him and his followers with power. Disguised in hoods, the Doctor, Federico and the guards enter and witness the ceremony. Federico steps forward, calls Hieronymous a traitor, and rips off the golden mask, only to reveal glowing energy in place of a face. Hieronymous raises a finger, and electrical energy stabs out at the Count, reducing him to ashes. Hieronymous then fires at and kills the guards but does not seem to have seen the Doctor. The Doctor joins the circle around the Helix as Hieronymous announces that Mandragora will swallow the moon the next evening and then the Brethren will strike. The Doctor slips away unnoticed. In the palace dungeons, Rossini is about to kill the prisoners when the Doctor arrives and reveals that Federico is dead. The guards change their allegiance to Giuliano and take Rossini into custody. The Doctor observes that the Brethren are still a danger. He tells Giuliano to fortify the palace in preparation for their attack. In the meantime, the Brethren are driving people out of the city, isolating the palace. Giuliano wants to cancel the masque that will celebrate his accession, but Marco is confident they can defend the palace against the Brethren. The Doctor calculates there will be a lunar eclipse that evening – Mandragora swallowing the Moon – and when the Helix takes over, it will remove all sense of purpose from mankind. Right now, however, the Helix energy is spread thinly over all the Brethren, and it could be exhausted. He asks Giuliano for a breastplate and a length of wire. Wearing the breastplate under his coat, if he has guessed right about the nature of Helix energy, he could drain it off. Hieronymous knows of a secret way into the palace, and he intends to infiltrate his men under cover of the masque. The Doctor enters the temple and grounds the altar with wire. Hieronymous addresses the Doctor as "Time Lord", and says that Earth has to be possessed; if mankind's ambition is not checked, it will eventually spread into the Galaxy and the powers of Mandragora will not allow a rival within their domain. Hieronymous fires repeated bolts of energy into the Doctor's chest, knocking him back painfully, but the Doctor survives. At the masque, the Brethren make their appearance, and the masqueraders run about in panic as they fire into the crowd. Hieronymous