That’s how I read that logic as well: if Alia told the Emperor that she was the brother of Paul Muad’dib, and the Bene Gesserit Truthsayer was present, then he might trust Alia’s assertion.
I think the assumption is that the Sardukar have already interrogated Alia, and that she (being utterly confident in her brother's victory) saw no problem in gloating that Muad'dib is actually Paul seeking revenge for the Emperor's involvement in the fall of House Atreides. The only way Alia could possibly know of the Emperor's involvement is if she truly is Paul's sister.
That’s how I read that logic as well: if Alia told the Emperor that she was the brother of Paul Muad’dib, and the Bene Gesserit Truthsayer was present, then he might trust Alia’s assertion.
I think the assumption is that the Sardukar have already interrogated Alia, and that she (being utterly confident in her brother's victory) saw no problem in gloating that Muad'dib is actually Paul seeking revenge for the Emperor's involvement in the fall of House Atreides.
The only way Alia could possibly know of the Emperor's involvement is if she truly is Paul's sister.
Such a great summary of this entry into Dune. It’s almost like you do this professionally???