That's what the GP is saying. It's very difficult to keep a conspiracy secret unless one of the conspirators ensures all of the others are dead.

Or only one. As an example.

> Assuming Charlene isn't a murderer or a ghost

Honestly it's a coin toss

Now I'm picturing a séance and the medium is saying "That's nice Charlene, but this lady would really like to speak to her late husband, Bob, now."

brilliant