Through the use of foreshadowing, Harper Lee manages to create an atmosphere of suspense during the children's journey home through the dark near the end of To Kill A Mockingbird. She does this from the very first line in Chapter 28:
*"The weather was unsually warm..." The fact that the weather is described as both unusual and warm gives the reader a feeling that something is already "off" and not right.
* "The wind was growing stronger."
*"There was no moon". These last two examples yet again set up an "all is not well" tone to the chapter.
* At one point while they're walking, Scout trips and Jem tries to help her. Because of her cumbersome costume, walking and maneuvering is made difficult, slowing down the children as they make their way home.
*Once they cross the school yard, it says, "It was pitch black". The children are now unable to see what lurks in front of them. They cannot even tell where they are.
*Their walking slows to a "cautious" gait. Once again, Lee's word choice is very important in setting up this scene of suspense.
* Lee writes that the lights in the auditorium were very bright, but if anything, it blinded the children and made it more difficult to see.
*Cecil Jacobs jumps out of nowhere and scares the daylights out of the two kids.
*Later on, when the children become aware that someone is once again around them, they believe it to be Cecil.
*They begin to hear shuffling, but it stops when they're walking. They believe it to be Scout's costume rustling.
*They then realize that whomeever is following them is gaining ground and running to them. That is when the children decide to run.
These are the specific examples of how Lee creates an atmosphere of suspence in the chapterl however, a simpler answer would be through the author's word choice and use of foreshadowing. Hope this helps!