Definition: In this task, you will use your knowledge about language (and common sense) to determine what element the marked number refers to. The numbers are marked with two underlines around them, like: _ number _. Your answer should be chosen from the given text, and should not contain other words.
Input: Richard Castle:  Hey .
Kate Beckett: Hey . There 's no news from CSU on the name tag . Not that I was expecting any .
Richard Castle: Makes you wonder why he did n't pull that whole gas leak routine on Linda Russo .
Kate Beckett: I know why . The answer 's in here .
Richard Castle: A transcript ?
Kate Beckett: From four years ago . I took a look at calls made to the Triple Killer tip line , and this _ one _ stood out for me . It 's from May 21st , 2006 , which was a week after the sixth murder . A woman called and left a message , but she was too afraid to leave her name . But she did mention that she lived at 24th and 10th .
Richard Castle: Same corner as Linda Russo .
Kate Beckett: She was riding an elevator with a cable repair man who so creeped her out that she got off a floor early just to get away from him .
Richard Castle: Yeah , but cable guy and creepy , that 's a job requirement .
Kate Beckett: Except he was n't a cable guy . She said he was n't carrying the right tools .
Richard Castle: And working for a cable company , Linda Russo would know that .
Kate Beckett: Which is why I took a look at Linda Russo 's phone records from four years ago . She 's the one who made the call to that tip line .
Richard Castle: So Linda Russo was special .
Kate Beckett: When she got off a floor early , he knew that she made him , so he dropped out of sight .
Richard Castle: Which also explains why he attacked her outside . He knew there was no way she 'd let him into her apartment .
Kate Beckett: Linda Russo saw his face , and he came back four years later . That 's a special kind of ruthlessness .

calls