C1045 Why is this fellow here?

It was almost dusk and the city gate was about to close. Many people were entering and exiting the gate, making the place very lively.

Bai Xiaohei walked along the crowd, because there were simply too many people entering and exiting the city, the procession's speed was not fast, and Bai Xiaohei was bored out of his mind, so he looked around at the people who were entering and exiting the city