#his apprentice died

[cadesama]

I think the idea that Dooku, as a former Jedi Master, must necessarily be the Sith Master is underrated in fandom and in canon (where the obvious conclusion post AotC is never broached). And from there, it become easy to assume a younger apprentice.

And from there, to never suspect Palpatine of anything except potentially being the victim of a Sith.