This was some really good advice, so I think I've got some outlines.
First, I'll turn to my resident Xanatos, the formorian giant Onagar Granitebones who is the patron of my Warlock player. The party doesn't trust him, but they have gotten used to doing his bidding because he rewards them well. They also know that he is intelligent, greedy and sadistic. I had already planned to have Onagar make a secret alliance with the Lich Queen Vlaakith for the purposes of getting a share of loot and slaves in the war, so this stretches my use of him.
I'll get Onagar to tell the PC's that a powerful weapon exists in a stronghold belonging to Vlaakith, an apocolypse stone. Time is of the essence, because this abyssal shard will unleash a storm of elemental chaos which will shatter the world and dissolve it back into elemental chaos. The only way to destroy it will be to toss into the super-caldera, which is a gate to the elemental chaos. There the crystalized power of the elemental chaos will dissolve harmlessly into the infinite energy of the plane from which it came, like a sugarcube in water.
The volcano-gate will be guarded by devil-worshipping fire giants (I already have a module in Dragon for that!) that given the Githyanki's fondness for infernal pacts and infernal servants would seem to be in league with the Githyanki. They aren't, they are just loyal to Mephistopholes, who is opposing the plans of Asmodeus out of spite.
The PC's defeat the giants and drop the apocolypse stone into the volcano gate, causing first a massive earthquake, and then a massive eruption, and then causes new fault lines to radiate out from it, turning one continent-spanning techtonic plate into several.
The Githyanki incursion will take the opportunity to strike with renewed vigour, while the nations struggle to survive the fimbrulwinter and find food. The PC's will be both instrumental in helping to fight off the Githyanki offensive and choosing various parts of the campaign world to save. They will also have a bone to pick with Onagar, who played them for patsies and is currently looting their home city (his reward from the lich queen).
Meanwhile, the Lich Queen waits for the polar ice caps to grow and reveal the lost city beneath the ocean waves. There a living god king was murdered by his most trusted and powerful servant Asmodeus. She will enter his tomb to retrieve the key to unlocking his power.
Now, this assumes that the PC's will throw the apocolypse stone into the volcano, so I'll resort to a bit of a cheat. The apocolypse stone is only one way to trigger the caldera. A fire titan will lair beneath surface of the volcano's magma, and will be angered if the players attempt to remove the apocolypse stone from its resting place. When they defeat him, the death throes of the titan's body will serve as the catalyst for the eruption of the volcano. The apocolypse stone will be revealed to be a very expensive and powerful magical item but was never really dangerous at all. That will be their reward for getting it right.
First, I'll turn to my resident Xanatos, the formorian giant Onagar Granitebones who is the patron of my Warlock player. The party doesn't trust him, but they have gotten used to doing his bidding because he rewards them well. They also know that he is intelligent, greedy and sadistic. I had already planned to have Onagar make a secret alliance with the Lich Queen Vlaakith for the purposes of getting a share of loot and slaves in the war, so this stretches my use of him.
I'll get Onagar to tell the PC's that a powerful weapon exists in a stronghold belonging to Vlaakith, an apocolypse stone. Time is of the essence, because this abyssal shard will unleash a storm of elemental chaos which will shatter the world and dissolve it back into elemental chaos. The only way to destroy it will be to toss into the super-caldera, which is a gate to the elemental chaos. There the crystalized power of the elemental chaos will dissolve harmlessly into the infinite energy of the plane from which it came, like a sugarcube in water.
The volcano-gate will be guarded by devil-worshipping fire giants (I already have a module in Dragon for that!) that given the Githyanki's fondness for infernal pacts and infernal servants would seem to be in league with the Githyanki. They aren't, they are just loyal to Mephistopholes, who is opposing the plans of Asmodeus out of spite.
The PC's defeat the giants and drop the apocolypse stone into the volcano gate, causing first a massive earthquake, and then a massive eruption, and then causes new fault lines to radiate out from it, turning one continent-spanning techtonic plate into several.
The Githyanki incursion will take the opportunity to strike with renewed vigour, while the nations struggle to survive the fimbrulwinter and find food. The PC's will be both instrumental in helping to fight off the Githyanki offensive and choosing various parts of the campaign world to save. They will also have a bone to pick with Onagar, who played them for patsies and is currently looting their home city (his reward from the lich queen).
Meanwhile, the Lich Queen waits for the polar ice caps to grow and reveal the lost city beneath the ocean waves. There a living god king was murdered by his most trusted and powerful servant Asmodeus. She will enter his tomb to retrieve the key to unlocking his power.
Now, this assumes that the PC's will throw the apocolypse stone into the volcano, so I'll resort to a bit of a cheat. The apocolypse stone is only one way to trigger the caldera. A fire titan will lair beneath surface of the volcano's magma, and will be angered if the players attempt to remove the apocolypse stone from its resting place. When they defeat him, the death throes of the titan's body will serve as the catalyst for the eruption of the volcano. The apocolypse stone will be revealed to be a very expensive and powerful magical item but was never really dangerous at all. That will be their reward for getting it right.