The Forgekeeper was accidentally imprisoned in the Mithral Forge when the Dwarves that manned the forge fled a Cerberus summoned by Lutheria hundreds of years ago. Five centuries of solitude led to her even forgetting her own name.
Originally, the Forgekeeper had been contracted by oath to help a group of dwarves run forge on behalf of the Dragonlords to assist their war efforts; but a clause in the contract meant that she could not leave of her own volition when everyone else fled.
Because of this, the Forgekeeper has a great dislike for Dwarves, having been trapped by them, albeit unintentionally, in the Mines almost 500 years ago.
Her imprisonment was ended when, panicking during the Oracle's Chosen's fight with a Cerberus in the Mithral Mines, Braz swore an oath to free the Forgekeeper if she helped fight the beast.
In a show of good faith, after the fight was won and she was freed, the Forgekeeper gave Helikaon a suit of armour and lit the forge before leaving to return to the Plane of Fire.