Many fictional time travel books play with the idea of changing the past in complex ways. In 'Kindred', the main character's presence in the past does cause some changes, but it also shows how the past has shaped the present and future in ways that can't be easily undone. In 'Slaughterhouse - Five', Billy Pilgrim's time - traveling experiences don't really focus on changing the past in a traditional sense. Instead, it shows how the past, present, and future are all interconnected. In some books, like 'Time and Again', the concept of changing the past is more about the main character's personal journey and self - discovery rather than making large - scale historical changes.
Some fictional time travel books suggest that changing the past is impossible. For example, in 'The Time Machine', the past is set and the time traveler can only observe. Others, like '11/22/63', show that while it may seem possible to change the past at first, there are unforeseen consequences that ultimately keep the overall course of history the same. In this case, the protagonist tries to prevent Kennedy's assassination but realizes that the past resists being changed.