Pulsing Cavern

The Pulsing Cavern is a cavern where the Black Swords, Stormbringer and Mournblade, were safeguarded by the Lords of the Higher Worlds after the swords were relinquished by the ancestors of Elric. The cavern is located beneath a marsh near the city of Ameeron, and reached through the Tunnel Under the Marsh that leads from a door at the base of the Monument of the Eagle.

The cavern is made of a strange fleshy material that pulses steadily, almost like a living, breathing organ. Mortal weapons may not be used in the cavern (they simply fall to the floor when wielded). Mortals may enter the cavern only if they know the proper spell, as Yyrkoon did when he sought the runeblades for himself, but if they do not leave before the spell ends then the entrance will close and they will be trapped inside forever. The walls of the cavern are impervious to weapons, including the Black Swords, so those trapped within may not simply hack their way out. Only the Lords of the Higher Worlds (including Arioch) may come and go as they choose.

Yyrkoon trapped Elric there, forcing them to pit the Black Swords against each other in a duel to the death. Elric won and spared him, then convinced Arioch to free them and Rackhir the Red Archer from the cavern. After Yyrkoon was defeated, Mournblade vanished from the cavern and Elric obtained Stormbringer.

Arioch later entranced Elric to retrieve Mournblade from the Pulsing Cavern and return it to Yyrkoon in order to lead Elric back on the path towards his destiny. Then Arioch made Elric forget what he was made to do there.