English
The Doctor, believing Amy's attraction to him is due to the stress from travel, gatecrashes her fiancé Rory's stag party, and invites the two of them on a romantic trip courtesy of the TARDIS. They land in Venice in 1580 and soon find trouble. The city's patron, Signora Rosanna Calvierri, claims that the Black Plague runs rampant outside of Venice, but the Doctor says this is false and it appears she is using this as an excuse to seal off the city. When they try to learn more, they encounter Guido, a boat-builder who is desperately seeking information on his daughter Isabella. Guido explains that Signora Calvierri runs a highly-praised school for the betterment of young ladies, which he was able to enroll Isabella into, but he now fears something is wrong. The Doctor and Amy and Rory investigate separately; they all come to the same conclusion: Signora Calvierri, her son Francesco, and the girls in the school are all vampires, feeding on the blood of young women by biting their necks with long teeth. These vampires fear direct sunlight, and leave no reflection in a mirror.
Amy devises a plan to place herself inside the school with the help of Rory; after getting in, she will let the Doctor and Rory in through a canal entrance. Though she is able to unlock the necessary gate, Amy is discovered and taken to a chamber to be turned into a vampire. In her struggles, she kicks at Signora Calvierri and discovers that she is wearing a device that masks her true alien form. Isabella, who has yet to be fully converted, frees Amy and they escape along with the Doctor and Rory. Isabella hesitates on the threshold because she cannot handle direct sunlight; she is pulled back inside and the door closes. The Doctor tries to open the door but he gets shocked by electricity and collapses. Isabella is later thrown into a canal by Signora Calvierri and eaten by something that lives underwater.
The Doctor goes back inside to question Signora Calvierri; he confirms that she and the others are creatures from the planet Saturnyne, a race of aquatic beings with vampire-like tendencies, but wearing perception filters—the device Amy struck—to make them appear human; the filters are the reason for the lack of reflection. Signora Calvierri states they were fleeing from numerous cracks in time that threatened their planet, through some of which they heard only silence. Calvierri and her son fell through one crack into Venice, and are now seeking to sink the city and convert humans into "Sisters of the Water" in order to continue their race. When the Doctor returns to Guido's home to report, Signora Calvierri sends her transformed girls to attack them. Guido sacrifices himself for the others by blowing up several kegs of gunpowder that kill him and the girls. Signora Calvierri activates a device on a tower that begins to create the earthquakes and floods that will sink Venice. While Amy and Rory face and defeat Francesco, the Doctor climbs the tower and stops the device in time. The last of her kind, Signora Calvierri throws herself into the canal where her doomed offspring await, but not before tormenting the Doctor by reminding him that he is now responsible for the extinction of two species: her own, and the Time Lords.In the aftermath of the incident, Amy and the Doctor invite Rory to continue traveling with them, but as the Doctor and Rory are about to enter the TARDIS, everything falls silent. Unnerved, the Doctor remembers Signora Calvierri's words: "We saw silence, and the end of all things..."