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 _. There are several possible answers, you'll need to choose the proper one. Carefully read the given text, pay special attention to the marked number, think about what (unwritten) information the marked number holds inside, choose the most adequate word(s) from the optional answers. If none of them seems right to you, there's also an option for other. If your answer is "REFERENCE", also write the reference entity, otherwise write the implicit option name. Options to choose from are:
REFERENCE: Some object which is being mentioned in the text before or after the target number. The reference answer has a higher priority than any other. If both Reference and another answer are possible, prioritize the Reference.
YEAR: Describing a calendric year
AGE: Describing someone's age
CURRENCY: Reference to some monetary value e.g dollar, euro etc.
PEOPLE: Describing a single/plural persons
TIME: Describing a time of the day. Usually you can add the word o'clock after those numbers.
OTHER: Some other option, which isn't listed here.
Input: Kate Beckett:  The moment that I met you , my life became extraordinary . You taught me to be my best self , to look forward to tomorrow 's adventures . And when I was vulnerable , you were strong . I love you , Richard Castle . And I want to live my life in the warmth of your smile and the strength of your embrace . I promise you I will love you . I will be your friend and your partner in crime and in life , always .
Richard Castle: The moment we met , my life became extraordinary . You taught me more about myself than I knew there was to learn . You are the joy in my heart . You 're the last person I want to see every night when I close my eyes . I love you , Katherine Beckett . And the mystery of you is the _ one _ I want to spend the rest of my life exploring . I promise to love you , to be your friend , and your partner in crime and life , ' till death do us part , and for the time of our lives .

REFERENCE mystery