Garrick the Mad cures himself and Ilmak of the mindflayer seeds in their skulls. Ottian has Ilmak take him to Ironview to check out what has happened to the swordmagi under Veszafein's rule. Garrick is magically transported by Ottian to Avernus to join the rest of the party in the city of Bel in finding the jewelled Ziggurat.
The party is granted an early audience with Bel in his Bronze Citadel due to the rising status of Whosis Kid in the local barfighting scene. Whosis and Iggy arrive late to the meeting to find the rest of the party, Garrett, Garrick, and Kodrus Jr. enjoying Fire Wine with Bel and his vassals.
Bel accepts a magical item as a present and then discovers that Whosis kid's crown is a scrying device for Graz'zt the demon lord. Assuming they are servants of the dark six he casts them into the sea of maggots below his palace (actually a dry plain covered in a shallow swarm of maggots stretching for miles).
A crowd assembles on the battlements to watch the fight between the party and Tiamat. Whosis jumps on Tiamat's back until he is stung and killed by her poison tail. Garrett is stung and dies next. Garrick is stung but does not die. Kodrus lands the killing blow to Tiamat and he obtains her life essence, becoming a demi-god himself (he becomes stronger and tougher).
As they travel past the dragonspawn pits near the tower of skulls (made from vanquished demons from the bloodwar), they set up camp near a far cliffside that they must scale to reach the next layer of Baator called Dis.
While they are encamped in a magical circle, the devil thrax and a swarm of spine devils gather round and proclaim they are bounty hunters seeking the price that darkspire has placed on their heads. They capture Thrax and kill the spine devils. Thrax agrees to gain them an audience with Dispater the ruler of the second layer of the hells, in exchange for his life.
They meet Dispater in his hall and tell him that they wish to travel to Minauros to seek the jewelled ziggurat. He says they will likely find it there and gives them the book of vile darkness to return to Mammon, the ruler of the third layer. They ask how to get there and he says that Baba Yaga, the innkeeper at Baba Yaga's Hut can provide them with safe passage.
At Baba Yaga's Hut they get into a barfight with several gods and cliff the drunken minotaur. Then they are transported to the stinking swamps of Minauros. Baba Yaga takes a magical item as payment for transporting them.
In the swamps they head to Mammons sinking city and he greets them. They tell him that they seek the jeweled zigurrat and he says that as the Viscount of Minauros it's in his power to give the jeweled ziggurat to them. He asks that they defeat a rival on the next layer Phlegethos for him and he would gladly give it to them. Mammon swore an oath to Asmodeus not to challenge Gazra the pit fiend on the next layer, but any other can defeat him and name his successor. Mammon wants to serve on that layer because he detests the swamps and wants to live near the fires of the volcano city where Gazra leads the Armies of Phlegethos for it's lords.
Mammon invites the party to enter the Ziggurat and they find it is very large inside and has open gardens and the black library of legend where Ioun dwells. Garrett meets Ioun and his hand raises to attack her with the sword. He controls the sword with his focused faith but Ioun tells him to fulfill the prophecy by allowing it to slay her. Garrett beheads Ioun and gains her power becoming a demi-god and gaining ultimate power over the hand of Vecna. He is now bound to defeat vecna with his own hand, fulfilling the prophecy or die trying.
The party also learns that Wee-Jas (the raven queen), vecna, and Ioun all once served together in the same magical order. Wee-Jas learned the secret of immortality and vecna killed her to obtain it. Wee Jas resurrected as the raven queen and gave the secret to Ioun to avenge her death. The conflict among the three has been going on for over a thousand years.
Ioun also shows the party that in the past month they've been in hell, Orcus has freed himself and flown to Barovia. Brock Mez'Gar has lead an army of Gnolls to conquer the Imperial Capitol of Draconis, where he now reigns as Barbarian King. Veszafein has opened a portal to the shadowfell and freed Vecna, who now rules Ironview, with Veszafein as his lieutenant.
