Quotation
-I thought he would have a fine surprise, but his face killed my joy.
-Atticus got up from his chair, but he was moving slowly.

Scout creates tension in chapter 13 as she is right in the middle of a dangerous situation that she is unaware of. However, she is also used by Harper Lee to release the tension.
When she saw Atticus, she said ‘I thought he would have a fine surprise, but his faced killed my joy’. This creates a lot of tension as Atticus has realised not just he’s in danger but Scout, Jem and Dill is in danger too.
However, when she finds a familiar face in the mob of strangers, she speaks to him about his son to him.