Herbert doesn't believe that Yukio "let" the Mother of Invention into his head either. It's all this brainwashing garbage like with the Prince all over again. (He doesn't even think the Mother's scientific methods are very good. She's obviously far too fixed on aesthetic. In retrospect, he's not interested.

Yes it took until now for the final coffin nail.)

Also he's fairly certain there's about to be a lot of fire, very soon--or at least some mind games--so he takes off running towards the back rooms. When in doubt, go for the biggest guns that you can feasibly trust.