In the caper example Armando gives in his book, the MC is an aging thief planning a heist. The IC is his ex-lover who has gone straight and is trying to convince the thief to do the same. Through the first two acts, the story reveals the OS, MC and IC signposts – the OS throughline of planning the heist, the IC throughline of the influence of the woman he’s still in love with, and the MC throughline of the thief who is maybe too old for the job.
It’s only at the end though that the RS throughline–which is in Psychology (Manipulation)–is revealed and we see that the thief and his lover were actually in cahoots–Planning, Playing a Role, (not) Becoming ex-thieves, in order to throw the other characters off the scent (Conceiving).
I think this is an instructive but not perfect example. First of all, it’s not really “a mystery” though it technically fits the definition of the characters knowing more than the audience. But then that creates a problem in that the MC player knows things that the audience doesn’t, which might or might not feel like cheating.
Having thought about this subject a bit, I now think it’s probably more useful to take a holistic/organic approach and recognize that you can separate the “storytime” events in the signposts and choose to reveal them in a variety of ways, at different times, in different orders, to create different emotional impacts on the audience.
For me, this means creating two outlines – one that describes the linear progression of the signposts and another that describes the order in which events revealed to the audience. (At the moment I’m doing this in revisions, not upfront).