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: Delenn:  Captain . I wish to speak with you about Mr. Morden . You must release him at once .
Capt. John Sheridan: You , too ? The both of you ? Who is this guy ? What is so important about him ?
Delenn: You will simply have to trust us , Captain . If you do not release him , everyone here is in considerable danger .
Capt. John Sheridan: No . Not until I get some answers once and for all .
Delenn: If this is the only way , then we will give you those answers . But be warned . Once you know his secret , once you know what we have known for the last 2 years , you will not sleep well again . Come , Captain . The greatest nightmare of our time is waiting for you .
Delenn: There are beings in the universe billions of years older than any of our races . Once , long ago , they walked among the stars like giants . Vast and timeless , they taught all the younger races to explore and create great empires . But , to all things , there is an end . Slowly , the First Ones explored beyond the rim never to return . Some simply disappeared .
Capt. John Sheridan: Delenn , I 'm sure this is all very fascinating but what does any of this have to do with Morden ?
Delenn: Not all of the First Ones have gone away . A few stayed behind watching and waiting for the day when they may be needed . When the Shadows come again .
Capt. John Sheridan: Shadows ?
Delenn: We have no other name for them . The Shadows were old when even the Ancients were young . They battled each other over and over across a million years . The last great war against the Shadows was 10000 years ago . It was the last time the Ancients walked openly among us . But the Shadows were only defeated , not destroyed . A thousand years ago , the Shadows returned to their places of power , rebuilt them , and began to stretch forth their hand . Before they could strike they were defeated by an alliance of worlds including the Minbari and the few remaining First Ones who have not yet passed beyond the veil . When it was over , the First Ones left . All but _ one _ .
Capt. John Sheridan: There 's still one of them left ? Where ?
Delenn: That is why Kosh can not leave his encounter suit . He would be recognized .
Capt. John Sheridan: Recognized by whom ?
Kosh: Everyone .
Delenn: For centuries , the Vorlons stood alone . The last remaining guardians . Then , last year , I sent Kosh a message .
Delenn: Did you see Ambassador Kosh ?
Lennier: I did .
Delenn: Did you relay my question precisely ? Word for word .
Lennier: I did .
Delenn: His reaction .
Lennier: Just one word . He said , ' Yes . '
Capt. John Sheridan: If yes was the answer , what was the question ?
Delenn: Have the Shadows returned to Z'ha'dum ?

Ones