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: Angel of Destiny:  There 's one more battle on the horizon for you three . One unlike you 've ever faced before , _ one _ you wo n't see coming , and one you may not survive .
Piper Halliwell: What does that have to do with Leo ?
Angel of Destiny: The loss , the pain will motivate you , all of you to fight , without which you will have no chance to prevail .
Piper Halliwell: Wo n't you please try to let us find a way to do this without Leo dying ?
Angel of Destiny: What exactly do you have in mind ?

battle