Complex sentence: The queen asks him to write his story for her, and Derfel writing his memoirs forms the frame of the series, as the novels progress it is apparent that the saxon's are approaching Derfel's monastery.
Split into simpler sentences: The queen asks him to write his story for her, and Derfel writing his memoirs forms the frame of the series. As the novels progress it is apparent that the Saxon's are approaching Derfel's monastery.