Foreshadowing???????? Later on it might explain why she wanted it
That the Robinson (black man) was accused of raping the Ewells daughter. Atticus plans to prove the court that it was not possible for Robinson to do the things he was accused of.
The meaning of bad according to the dictionary is of poor quality, inferior or defective. It can also mean something that must not to be desired. Synonyms would include awful, lousy, miserable, and unpleasant. The antonyms of bad are good, and favorable.
Probably the setting will be in a castle. There will be an atmosphere of mystery and suspense. Most likely an ancient prophecy, and omens, portents, and visions. Also some supernatural events. Definitely overwrought emotion. Woman threatened by a powerful male most of the time. Gloom and horror too. That's about it.