Karl Iglesias in his WRITING FOR EMOTIONAL IMPACT presents mystery in the emotional sense, not as a genre. Mystery connects the reader with the character. Mystery elicits the reader’s curiosity and anticipation. Iglesias explains writing mystery about the character’s past, present, and future.
He differentiates the mysterious past from backstory by “how much is actually revealed to the reader”. The writer keeps hidden information that the reader wants to know. In Casablanca, hints of Rick Blaine’s past suffering show him dodging and evading questions about it when asked. We don’t discover it until the Paris flashback.
Past abilities or the mysterious origin of the abilities are filtered out like clues. Iglesias gives the example of Jason Bourne in The Bourne Identity, where the reader is curious about Jason’s abilities “not remembering the past as a secret agent”.
The character’s secrets add mystery. The secrets could be dangerous, harmful, or embarrassing and the character will do anything to keep them hidden. An example is in Chinatown, Evelyn Mulwray’s dark secret.
In my YA novel, Lilli has a secret that isn’t divulged until the fourth chapter but I sprinkled hints along the way. For instance, she says she accidentally almost killed her unborn child’s grandmother. How and why isn’t told until later.
Remember, however, that the reader doesn’t want to be confused or frustrated with too little information that they give up on wanting to know the secret. Tantalizing is the key, but avoid irritating your reader.
See you tomorrow for the mysterious present.