the charge was sounded to retreat from the fallen fort , the riders mounted their steeds and charging out furiously through the ranks of the ibis though many perished , but even at the ruins of the gate they were cut off by the main strength of the ibis and when it seemed all hope had been lost and tirbane had turned to their graves , the morbid arrived , rangers of iop they were of great reputation in the wars of old , coming from the darkness of the woods at the rear of the enemy , unlooked for they rode into the rear of the ibis ranks and hurled their charge away , making room for the king and his men to flee from tirbane .