In Diary of Anne Frank, how does the author balance the suspense of Scene 4 with the sadness of Scene 5?

In Act 1, Scene 4, the author introduces a feeling of suspense to the story. This is achieved through the depiction of Anne's dream. We learn that Anne has a terrible nightmare in which her family is captured by the Green police. Everyone is annoyed at Anne, even though her feelings are understandable. This nightmare is introduced as foreshadowing. The author builds suspense by suggesting what is going to happen later in the story, when Anne is indeed captured.

This suspense of scene 4 is followed by the sadness of scene 5. In this scene, the families are celebrating Hanukkah. However, their spirits are low, and they have little to celebrate. In the middle of their celebration, they hear noise downstairs, and they believe that they are about to be captured. The reader is able to link this situation with that of Anne's nightmare, thus balancing the two events in his mind, and linking the suspense of the previous scene with the sad events of the latter one. Eventually, the families realize that a robber came in and most likely heard them. As now they are fearful about being captured, the rest of their Hanukkah is conducted in extreme sadness.