I’d like to include in a story “mysteries” and deceptions that (ideally) should be obvious in hindsight (By obvious, I mean "elephant in the room" kind of obvious).
How to give to the reader every element they need to unravel a mystery, while keeping them from resolving it?
How to hide something in plain sight?
I’m looking (preferably) for methods to keep the reader from seeing what is right in front of them.
Example (in a story with magic and stuff):
The Main Character meets early in the story auntie A, who appears to be an old man wearing women clothes. Since other characters have known auntie A for years and don’t seem to find it weird or unusual, the MC doesn’t comment on it. She regularly goes to Auntie A for advices and guidance afterwards.
During the course of the story, MC discover that she is immune to some specific types of magic (including illusions and mental manipulation), and learns why they don’t affect her. Also, a couple of characters who know auntie A show signs of bigotry towards sexual minorities.
While investigating the disappearance of one of her relatives, MC finds the months old corpse of a woman. At first she assumes that the deceased is the person she was looking for. She realises later that it’s the corpse of the real Auntie A, and that the man she met actually stole her indentity, used a spell to make himself look like her and lives in her home, wearing her clothes to increase the spell’s effectiveness.
I’m afraid that since the readers will have every element they need to realise the deception, the reveal won’t have any impact. Moreover, my only readers for now are close friends and I already talked with them about this idea, so I won’t know if it works when I’ll show them the first complete draft.