"Opus 21" likely explores themes relevant to its time, which was marked by the aftermath of World War II and the beginning of the Cold War era. Wylie's writing often delves into social and political issues, and "Opus 21" is likely to reflect his concerns and observations about the state of the world during the post-war period.The title "Opus 21" suggests a creative work, possibly referencing music or artistic expression. The novel may incorporate elements of drama, romance, or adventure as it follows the lives of its characters and explores their struggles, aspirations, and relationships.