Sensing that something was off, Zhou Siwei didn't hesitate anymore. She kept her cell phone in her pocket and instinctively got up to walk to the toilet.
The male and female toilet had a washroom. The male toilet was on the left and the female toilet on the right.
It was lunchtime and it was 2: 20pm. There was the sound of someone coughing in the male toilet, but there was no sound of water in the female toilet.
Zhou Siwei realized that there was no one else in the female toilet. She picked up the yellow maintenance sign in the corner and blocked it at the door of the female toilet to prevent others from entering and obstructing her work.
Before Yang Chong went to the toilet, Zhou Siwei had communicated with her to make it convenient for her to enter the second pit. If anything happened, she could accurately locate Yang Chong's position.