Atrius, Eilyac and Recrentius, celebrating at Filthy Brian’s in the days following the destruction of the wall of flesh, are approached by a stranger. She reveals herself to be Arvahnt, having returned to the city to fix the damage she witnessed Humble Hank and Magicami cause.
After witnessing the horror that befell the pair, Arvahnt had fled back to the forests of her youth looking for guidance. There, she stumbled upon Nink, the ferret God of healing and restoration. Nink took her as a Disciple, presenting her with the Velden Bow and a mystical seed before commanding her to return to Overcairn and purify the husk left by the wall of flesh.
After beseeching them to help her on her quest, Atrius, seeking to restore the balance of nature in the city, agrees to come. Recrentius is only convinced after Arvahnt promises to bring Recrentius to Nink, in the hope of finding a clue to the location of a new book.
The party travels underneath the city, fighting local bandits that make use of the tunnels, and eventually makes their way into an ancient flooded plaza, in the center of which is a petrified tree, their goal. Unfortunately, the ground is crawling with a hive of formians. Recrentius and Eilyac cause a distraction and lead the warriors away, while Arvahnt and Atrius make a run for the tree.
The tree is revealed to be protected by Mesphyr, the Chameleon God of Disguise and Deceit, and planting the seed causes her spirit to be revitalised.
As the tree grows, the party battles the formian queen, and in the culmination of that fight, the growing tree breaks through into daylight, and begins to reclaim and decompose the husk of the Wall of Flesh, becoming the Tantail Tree. In addition, the roots spread through the undercity, closing off the underground routes taken by slavers and thieves.
Oh, and I forgot to add, this whole time Eilyac was hauling around a massive carpet that he found because he was determined to sell it, regardless of how much irritation this caused.