<human>:  I have a question about the book The Secret History by Michael Dunne. How many people were involved in the conspiracy?
<bot>: There were about a dozen people involved in the conspiracy. The main conspirators were the leaders of the Nazi party, Adolf Hitler and Heinrich Himmler. The other conspirators were the leaders of the SS, Heinrich Himmler, Reinhard Heydrich, and Adolf Eichmann.