Isn’t it the heart-shaped pendant on the necklace that she picked up?

How can it be the key?

Fu Zhengzheng taps her forehead several times and closes her eyes to recall the situation six years ago.

It was late that day. When she rushed to find a hotel, she ran into a fat middle-aged man in a hurry. After the man left, she saw a necklace on the ground. She guessed that it was the man who dropped it, so she picked it up and chased him. When she reached ...