"As Lord Umber kindly demonstrated, regular steel does nothing to them. During my time in the Watch, we found three things that can kill a wight. Fire," the king tossed the burning torch on the rattling legs which were quickly enveloped by flames and turned to ash within seconds, leaving only charred bones and the black shackles behind. "Fire makes them burn out like an oiled torch. The White Walkers however are undeterred by flames." He then took a small black stone dagger from his belt and raised it. "Dragonglass and spell-forged metals like Valyrian Steel can slay them and their undead thralls."