Residing deep within the cavernous mazes of the Underdark, the elder brain controlled the hive colony of illithid which had existed for many thousands of years in the deep earth below Tolria. Growing corrupted after a continuum crystal was found by the roaming illithid thralls in a vacated mine, the elder brain began erratically killing its own and growing at an exponential rate. Threatening all in the Underdark and the undercity of Stormpeak above the colony, the elder brain was killed by an exploding B3T in a final showdown for the continuum shard within the brain.
