In my three book, fantasy series, I have a character who is a traitor to the group of protagonists.
The reader knows from the beginner that there is a spy somewhere because the anagonists discuss the fact that they have a spy, but it's very nebulous to begin with, though I am careful to leave a couple of hints here and there about who it might be so that it's not a huge surprise when the reveal is made.
At the end of Book 1 there's a turning point where the spy does something so overt that the protagonists will definitely know that someone is a traior (they will find out at the beginning of book 2) but they will not know who that traitor is until the end of Book 2. It's actually a turning point for the spy character where they decide to be a full on traitor and not just a passive spy who occassionally gives the antagonists tips but does little more.
The overt action involves the traitor physically meeting with the antagonist for the reader to observe. I could write this in such a way as to NOT reveal the traitor's identity (only confirm that it is someone the reader knows and possibly cares about) or I could write it in a way that reveals the traitor's identity to the reader so that they know before the protagonists discover it.
I'm struggling to determine which is better. I know this is subjective but I'd still like advice or an opinion that is outside of my own head!
On the one hand, I think it would be nice to only reveal that the traitor is part of the protagonists' core circle at the end of book one and leave the reader trying to figure out who it is, while leaving even more overt clues / misdirects along the way.
On the other hand, I don't want to insult the reader with a "tease" at the end of book 1 by writing a scene that's designed to keep the traitor's identity a secret even though the antagonist clearly knows who the person is. There is also some merit to giving the reader the identity and getting them excited about figuring out how the traitor will slip up and reveal himself to the protagonists.
At the end of the day, neither way I write this will affect much of how I write the traitor's plot or character-arc, it's just with one choice, the reader knows who it is quite a while before the characters.
I keep going back and forth, and it's driving me nuts.