A little trick for you to use in your writing.
Decide BEFORE you start writing down your story on the balance between mystery and suspense.
The idea is simple.
You must, absolutely must always always ALWAYS keep the reader either ahead of the story, or behind it. The moment you let the reader catch up to the present, they lose interest and put the book down.
How to keep them interested?
Mystery is when the readers are behind the story. They're on their toes and don't know what's going to happen next. That's one way.
Suspense is when the readers are ahead of the story. They know what's going to happen, but they don't know how, and they know it before the characters know it.
We won't be going into the whole genre discussion here so as not to complicate the idea.
You can pick one of the three balance tricks:
3. A mix of both
I recommend to start with one, if you're not very skilled in it, and progressing to the other, then progressing to the mix of both. T.U.B.E. is using a mix of both, but man, it was a lot of work.
So, which one will it be for your next story?