instruction:
In this task, you're expected to write answers to questions involving multiple references to the same entity. The answer to the question should be unambiguous and a phrase in the paragraph. Most questions can have only one correct answer.
question:
Passage: The story is set in Rome the early 4th century AD, during the time of the persecution of Christians under the Roman Emperor Diocletian.
The heroine of the book is Fabiola, a young beauty from a noble Roman family. She is spoiled by her father Fabius, who cannot deny her anything. Fabiola seems to have everything, including a superior education in the philosophers, yet under the surface, she is not content with her life. One day, in a fit of rage, she attacks and wounds her slave girl Syra, who is a secret Christian. The proud, spoiled Roman girl is humbled by Syra's humility, maturity and devotion to her in this situation, and a slow transformation begins, which finally culminates in her conversion to Christianity, brought on by Syra and of her own cousin Agnes, whom she adores and dotes on.
Another thread of the story deals with the young boy Pancratius, a pious Christian and son of a martyr, who is himself preparing for martyrdom. Pancratius' nemesis is Corvinus, a bullying schoolmate who is irritated by the young Christian's saintliness. He does everything to bring him and the Christian community of the catacombs of Rome down. This includes the orchestrating of the lynching of their former teacher Cassianus, who is secretly Christian. Yet Pancratius shows his enemy the meaning of Christian forgiveness when he saves his life shortly after Corvinus had Cassianus killed.
Another major villain in the story is the enigmatic Fulvius, an apparently rich young man from the East who soon reveals himself to be a hunter of Christians who turns them in to the authorities for money. His aim on the one hand is to gain the hand of either Fabiola or Agnes, and on the other hand, to uproot the Christian community in Rome. After some dramatic events that reveal his surprising connections to Syra, who is his long-lost younger sister Myriam, Fulvius rejects his evil ways, converts to Christianity and becomes a hermit. 
Question: Whose life does Pancratius save?
answer:
Corvinus.


question:
Passage: Richie Donovan works as a professional thief for Groznyi, a wealthy businessman, to pay off his debt for being smuggled into the U.S. as a child. He pulls off an initially successful diamond heist, but it is botched when he is involved in two separate car accidents. He is given one last chance to pay off his debt by going to Russia to steal a priceless antique cross, locked in a safe in a Moscow penthouse apartment. Richie and his Russian accomplices, brothers Peter and Yuri, recover the cross; but their elevator becomes stuck on the uncompleted 13th floor. Believing the police have stopped the elevator, the thieves take their fellow passengers hostage to negotiate an escape. They agree to send one hostage down; but, when the elevator doors open on the ground floor, the hostage has mysteriously been beheaded. 
The remaining hostages quickly divide into two groups: a Christian group consisting of Sonya, Helena and Katerina, who are later joined by Yuri, and another group consisting of nerdy Dmitry, beautiful Anna, and incompetent security guard Boris.
In the confusion, the Christian group seizes firearms and takes control, shooting Peter. Katerina is sent to stand guard over Richie and the remainder of the hostages, while Sonya takes Yuri to a chamber where he is to sacrificed by a wild man in armor named Alex. Yuri escapes, but he is impaled by one of Alex's traps, complete with disco music and lighting. In his rage, Alex kills Katerina, allowing Richie and the hostages to escape. They discover Alex's lair, where he has been watching everyone using security cameras. A photo reveals that Alex is the twin brother of Sonya, and they both believe themselves to be descendants of Ivan the Terrible. The group splits when Richie and Anna decide to chase after Alex, while Boris and Dmitry prefer to rig the room with various traps they have constructed and wait for Alex to come to them. 
Question: Who are the people who think the authorities are responsible for the elevator stopping, leading them to take hostages?
answer:
Richie.


question:
Passage: George Roger Waters (born 6 September 1943) is an English songwriter, singer, bassist, and composer. In 1965, he co-founded the progressive rock band Pink Floyd. Waters initially served solely as the bassist, but following the departure of songwriter Syd Barrett in 1968, he also became their lyricist, co-lead vocalist, and conceptual leader.
Pink Floyd achieved international success with the concept albums The Dark Side of the Moon (1973), Wish You Were Here (1975), Animals (1977), and The Wall (1979). By the early 1980s, they had become one of the most critically acclaimed and commercially successful groups in popular music; by 2013, they had sold more than 250 million albums worldwide. Amid creative differences, Waters left in 1985 and began a legal dispute with the remaining members over the use of the band's name and material. They settled out of court in 1987.
Waters' solo work includes the studio albums The Pros and Cons of Hitch Hiking (1984), Radio K.A.O.S. (1987), Amused to Death (1992), and Is This the Life We Really Want? (2017). In 2005, he released Ça Ira, an opera translated from Étienne and Nadine Roda-Gils' libretto about the French Revolution.
In 1990, Waters staged one of the largest rock concerts in history, The Wall – Live in Berlin, with an attendance of 450,000. As a member of Pink Floyd, he was inducted into the U.S. Rock and Roll Hall of Fame in 1996 and the UK Music Hall of Fame in 2005. Later that year, he reunited with Pink Floyd bandmates Mason, Wright and David Gilmour for the Live 8 global awareness event, the group's first appearance with Waters since 1981. He has toured extensively as a solo act since 1999; he performed The Dark Side of the Moon in its entirety for his world tour of 2006–2008, and in 2010 began the Wall Live tour, the highest-grossing of all time by a solo artist. 
Question: What is the last name of the person who became the co-lead vocalist of Pink Floyd in 1968?
answer:

Waters.