In frustration, 40 or 50 of the attackers tied together two ladders and crawled through the sluice-ways of the garderobe (latrines) that emptied on the hillside, thus gaining access to the interior of the castle. There they killed around 20 of the defenders in fierce fighting; the remaining defenders, approximately 70 men, among them Buchner and Sudermann, the garrison commander and his lieutenant, sought refuge in the castle's keep. In this way, Ferdinand's infantry at last gained unopposed access to the fortress. Storming the castle had taken about two hours. Out of options, Buchner opened negotiations, using those interned in the castle as hostages. Presenting them at the keep's door, he made clear that they would be killed unless Ferdinand promised to spare his, his wife's and Sudermann's lives. Ferdinand acceded to Buchner's demand; some sources maintain that the Abbot of Heisterbach, one of the prisoners, had been treated decently by Buchner throughout his imprisonment in the castle and himself asked for Buchner's life to be spared. The prisoners were released. With much difficulty, given the state of mind of the besiegers, Ferdinand and Arenberg brought the Buchners and Sudermann out of the castle alive. Once the Buchners, Sudermann, and the hostages were clear of the fortress, Ferdinand released his troops, who were in an ugly mood and hungry for blood and plunder. All those who remained in the keep—soldiers, men, women and children—were killed, some inside the keep, some in the courtyard below; the slaughter lasted well into the night. The castle's 178 dead were buried in two mass graves whose locations remain unknown. Among those who perished in the destruction and storming of the castle was also one of the prisoners, a vicar from Hildesheim. The Hildesheim suffragan, too, was not among the rescued prisoners; he had died during his incarceration, a short while before the castle was stormed. Gebhard lost an important stronghold in the "Oberstift" and Ernst's forces had acquired a ruin. The residence was unusable, and the fortifications were mere rubble. The keep had survived the blast and various armies used it as a watch tower in the Thirty Years' War. Ernst's troops, under his brother's command, saturated the region, and the between Godesberg and Bonn bore a greater resemblance to a military camp than to a road.