So...my party managed to alienate the Black Arrows and thus lost them as a source of information. Regardless however, they managed to get to Ft Rannick, and find their way into the tunnels beneath the waterfall. They went all the way North and came out from the North secret door. Then, using a variety of spells like Soften Earth and Entangle, created a kill zone that they used to slaughter the ogres inside the outer walls (Empowered Fireballs (scroll and Rod of Empowerment), Lightning, Call Lightning, and an Enlarged Fighter and Cleric. With that in place, they managed to wipe out all the ogres in the Fort, with only the loss of one PC (the cleric). Now, they are discussing negotiating surrender of those inside the keep. How should I handle this? The occupants can look out and see this pile of ogre bodies.