"The Summer I Turned Pretty" is back for its third and final season, bringing Jenny Han's beloved book trilogy to a close. But Han has teased that book fans might not know how the Prime Video series will conclude.

The Summer I Turned Pretty' series on Prime Video has made several changes from Jenny Han's trilogy of books in all three seasons.

For those who haven’t read The Summer I Turned Pretty books, several characters — including Steven and Taylor — didn’t have super strong presences in the text, so when it came time to write the Prime Video series and flesh out that world, Jenny Han decided to thoroughly expand their storylines.