C37 Defeat the bully by borrowing a knife(part i)

Just as I was about to leave, I suddenly saw a round indentation on the necklace. Why does the size of the indentation look so familiar? Ah! That's right, it's the cat's eye stone that the beggar gave me. I quickly took out a pebble and pressed it against the wall. The Cat's Eye Stone released a rainbow colored light. After the light faded