Inside the revolutionaries' headquarters, you will find a map of the castle and the surrounding town.  Also, you will find a long list of grievances against the King, both by his subjects and the Queen herself.  In addition, there are crates full of weapons and armor, as well as a small vial of poison.
hidden revolutionaries' headquarters, Inside Palace
duke
queen
I need a new cushion for this throne! All this chatter in court is giving me a headache!  That Lord that just walked past offended my nose with his odor.  I need to find my chambermaid.
hi My word! The Queen! W-What brings you to this place? How did you even find it?! One of the maids brought me here A traitor in our ranks! Oh how could we be so easily discovered?! Well, you are here now, Majesty. What say you? Will you tell your husband, the King, that we plot against him? But the king trusted you..especially you the Duke. This is not just fair The King has betrayed his people long before this rebellion came to be. Look upon the long list of grievances upon the wall! Point to even one and tell me it does not ring true! this is bad. Did you make any attempt to peacefully resolve this? Peacefully resolve this! How? Look at grievance number 5: imprison and torture any that questions his authority! I should be on my way, I cant be here Fine! Run! This only gives us the push we need to strike at the king! Tell your precious monarch all you have seen! We will be ready for him and his army! Just allow me to leave in peace I have sheathed my sword. Run. Run and do not return.