The long prologue that the Wife of Bath presents before her tale already suggests that her story will be an unusual and surprising one. This is because of all the strange elements that the prologue includes.
For example, we learn that the Wife of Bath likes to digress. She gets carried away with her story and mixes up plots, which leads to confusing and comical results. Moreover, we learn that the Wife has very unusual opinions when it comes to marriage. Contrary to most women at the time, she was a dominant character in all her relationships, and was able to take advantage of her husbands. This is despite the fact that she dealt with common sexists problems of the time, such as being beaten by her husband. The autonomy and self-confidence of the Wife of Bath contribute to making the prologue unusual, which hints at the surprising nature of the tale itself.