After the recess, we had free class, so we decided to go to the locker. When we went there, we saw the locker and opened it. It was not locked as the person was expecting me to give something in it. I kept a blank paper there cause I didn't even knew who it is. We slowly left the locker and hid behind a wall such that we could get a good view of the locker and the student will not even see us. After a few minutes, I saw a person wearing a black hoodie acting suspiciously. He slowly headed to the locker and opened it. He took the paper I left there and vanished into thin air or it can be that I didn't see properly. I asked Stella if she saw the same thing I did or not, but she had not seen anyone. She told me that she just saw the locker getting open and then close. She tried to make me believe that it was a trick of air and light but I can't be wrong. I am sure that I saw someone. What's happening with me. To confirm, I went to the locker and saw that it was locked. I looked at Stella and she gave me a dumb questioning look. Whatever the trick was, I don't know. I saw a person clearly, and I was gonna look into that matter. I asked Stella if she wanted to accompany me into this adventure and mystery but unfortunately she refused. She was like any other person I knew here.