Exposed!

Half an hour.

Plenty could happen in half an hour.

Inside Marquis Percy's castle, Drayce and his men searched where the Thevailes general took Prince Arlan. There were several guest rooms prepared for the general that was marked in the map given by the Abethan spy, as it seemed the general had the tendency to move about between the castle and the army barracks. 

One of their knights who managed to disguise himself as a servant came to them, and Slayer asked, "Where?"

When they made their plans to break into the Barknor Fortress a few hours ago, they had considered various scenarios such as this. Some of the knights who infiltrated inside were meant to become eyes and means for the entire rescue squad to pass timely information about the situation.