Heart of Lorkhan

The greatest influence the god Lorkhan had upon Nirn was his heart; taken from him by the other gods in their fury of his creation of the world. It was cast down into the depths of the earth, never meant to be found.

Unfortunately, sometime in the Second Era, the Dwemer discovered the heart whilest digging under Red Mountain. The Dwemer High Priest Kargrenac began to experiment with it, and created the profane tools Keening, Sunder, and Wraithguard to work with the heart. He would soon begin construction of the Numidium (a massive mechanical golem), hoping to use the heart at a power source, as well as experiments in improving the Dwemer race.

This plan was inturupted by the arrival of Indoril Nerevar, his generals (Vivec, Almalexia, Sotha Sil, and Voryn Dagoth) and an army of Chimer. At length, Nerevar and Dagoth fought the Dwemer king and Kargrenac in the heart chamber beneath Red Mountain. When the Dwemer were bested in combat, Kargrenac used the tools on the heart, and the entire dwemer race vanished.

Nerevar entrusted the tools to Voryn Dagoth (who had requested that the tools be destroyed), and met with his other generals. They agreed to keep the tools, but not use them. Upon returning to the heart chamber, they discovered that Voryn Dagoth had gone positively mad, and refused to relinquish the tools, stating the Nerevar had commanded him to keep them from falling into the wrong hands. Nerevar and Dagoth fought, and Dagoth was driven away, forced to surrender the artifacts.

This turn of events concerned Nerevar; and he decided to ask the Daedric Lord Azura for guidance. However, his generals murdered him during the ritual. Azura still came, and cursed the Tribunal for their crimes, claiming that she would use her powers to resurrect Nerevar. She then changed the Chimer into the Dumner.

The Tribunal then did use the tools on the heart, and became living gods; and did many great deeds for their people. However, their deeds worked against the evil nature of the heart, and thus they needed to return to it from time to time to rejuvinate their powers. At some later point, they discovered that Voryn Dagoth (now styling himself as Dagoth Ur) yet lived, and had connected himself directly to the heart's power. He drove them away, and on subsequent attempts to recover the heart chamber for themselves, they lost control of Keening and Sunder to him (and barely escaped alive, supposedly due to the quick actions of Vivec).

Over time, the Tribunal became weaker and weaker, whilest Dagoth Ur became stronger still. They disappeared from public view, and their influence faded. Their sole attempts at restraining Dagoth Ur (the Ghostfence) consumed much of their remaining power, and was largely ineffective at containing the Blight, and could not prevent Dagoth Ur's forces from flying or tunneling past this barrier.

Towards the end of the Third Era, Nerevar was indeed reborn; and after a great many trials, he came face to face with his old ally, and broke him. However, while sustained by the heart, Dagoth Ur could not truely die; and so by using the profane tools on the heart again, without a proper ritual, the Nerevarine severed the powers of the heart from the mortal plane, and was able to deliver a final death to Dagoth Ur, and the destruction of his great weapon: Akulakhan.

It is important to note that within the game it is realistically impossibly to kill the heart outright (unless using cheats). This is because it has a great deal of health, and rediculous regenerative powers; only the Keening and Sunder can banish it. However, if it is destroyed through cheats, the main quest can not be completed, as the heart's power is still bound to the plane, though it can no longer be accessed.