They are all ghosts!

Ding ding ding... A strange bell sound slowly rang, and bursts of white fog suddenly drifted on the empty street. 

The next moment, a dilapidated, blood-stained bus slowly drove out of the white fog. Alexander quickly waved his hand to stop the bus.

The bus door opened, and the driver was a young man with a pale face and forehead full of bloodstains. Seeing that the passenger was a human being, the young man was slightly taken aback, then opened his mouth and laughed silently.

Alexander glanced at the bus. There were already six men and three women on the bus. 

Four of the men and two women were sitting on the bus seats, obviously chosen ones who had just entered, their faces pale with fear, shivering all over. 

And the woman was an old lady with bifocals, dressed in all black. There were empty seats, but she did not sit down.