Some books have what I think of as side doors, entry points to parts of the story that are suggested rather than shown explicitly. They're not part of the main plot flow of the story, but they hint at an intriguing backstory or side journey. Sometimes they point to another book in the author's oeuvre; sometimes they foreshadow upcoming events in a series; and sometimes they let the reader connect certain dots and wonder at the rest. I imagine they could be great jumping-off places for fanfiction.
One example is in Gone with the Wind.
If you read between the lines, putting together certain information, it
is strongly suggested that Rhett Butler had a son with Belle Watling,
and the son was living in New Orleans. I've always thought that hidden
subplot had a lot of potential--what if the son came to Atlanta when he
Another example, from children's literature, is in Zilpha Keatley Snyder's The Headless Cupid.
For fun one day, the kids in the book are testing their psychic
abilities with playing cards. None of the kids displays any such
ability, until the last child--but just when he shows a glimmer of
psychic aptitude, there is an interruption and the scene goes in another
direction. This child's ability never really becomes a major plot
element, but remains a subtle thread, making us wonder about its
influence on the story.
Then there are the characters from books who make appearances in other books. S.E. Hinton's Tex is best understood after reading her earlier That Was Then, This is Now,
in order to make the connections between Cathy and Miss Carlson,
between Mark and the hitchhiker. The implication is also that Tex is
Mark's half-brother, and I've always wondered if Tex was written partly
to provide the redemption that Mark never achieved.
In Marilyn Sachs's The Truth About Mary Rose,
a young girl wonders about the deceased aunt she was named after, Mary
Rose. The plot revolves around the difficulty of interpreting history,
and how differently people see and remember the same person. The book's
narrator concludes that she can never know the whole truth about Mary
Rose. But readers have access to some materials that the younger Mary
Rose doesn't: Sachs's earlier books, in which the original Mary Rose
actually appears (albeit as a secondary character), especially Veronica Ganz.
I use "side doors" in my fiction all the time. An example is in Try Not to Breathe,
when the main character, Ryan, and one of his best friends, Val, visit
their other friend, Jake, at a time when Jake is in serious distress.
There are these two lines, from Ryan's POV: "When I came back into the
dayroom, Jake was bent over Val's lap, hanging on her, while she stroked
his hair. I hung back, watching, and the way he clawed at her made me
wonder if maybe I hadn't been the only one in love with Val all this
It made me wonder, too. In the book, it becomes clear how
Val and Ryan feel about each other, but Jake's feelings are left
murkier. Does he love Val? Does he maybe love Ryan? I would have loved
to explore those questions--and I did, but not on the published page.
They would have dragged the story off course. In essence, they were more
part of Jake's story than Ryan's, or maybe they were part of what would
be a sequel if I ever wrote a sequel for that book. As it stands, these
lines are just a side door for readers who want to speculate and carry
that story further in their own heads.
Do you ever notice side doors in the books you read? Do you follow where they lead?