Even though the lord of the territory, Marquis Godfrey Percy, was captured, the important soldiers and officials stationed at the base were killed, and the remaining soldiers inside the castle had surrendered; Drayce and his group could not afford to stay inside Barknor Fortress for long. Soon, Thevailes and Hatha would realize that an important fortress had been compromised and send reinforcements which would undoubtedly put everyone in danger.
The fight might have been brief, but due to the overwhelming numbers of the enemies, several elite knights from the squad had been injured, and some of them even died. No doubt, such a situation would severely affect the speed and security of their return trip.