The snippet opens with the normal situation for this particular scene.
In this case, that's Paul sitting on the bed in one room of the 'haunted' house.
Then a cause-effect chain begins. Note that there are no connectors, but we can still follow the links:
- A face appears.
- So Paul yelps.
- He notices grims details in the face.
- So he looks wildly around for an explanation.
- He sees even more floating faces.
- He thinks he should run to the door but can't.
Notice how in this particular passage, the main character is responding to steady pressure from other characters.
While the highlighting might look back and forth, the pressure is all in one direction. This is important because that continual pressure is what creates the change in Paul.