The Elven City Requires My Aid

The Elven City Requires My Aid is a main plot quest taking place during Baldur's Gate II: Shadows of Amn and Baldur's Gate II: Enhanced Edition. The quest begins in Chapter 6. 
== Aquisition ==
The party receives this quest and the player's Journal registers the initial entry after the questioning from Elhan and verification by the Elven War Sages.
== Walkthrough (abbreviated) ==
Once Elhan and Gorion's Ward have finished the elven commander's questioning and dialogue, the party receives Elven Holy Water and Wooden Stake supplies to assist with the next objective.
Suldanessellar, an elven city in the Forest of Tethir, built amongst the treetops - has seemingly disappeared. This is likely the work of Jon Irenicus. Elhan is evasive and unwilling to provide much information about why this city was targeted by Irenicus - There is some kind of connection between the elves and whatever power play your antagonist is scheming.
Elhan explains that an elven artifact known as the Rhynn Lanthorn will surely reveal the now hidden entrance to Suldanessellar - and even Irenicus's dark magic cannot keep the city obscured. He is unsure of the artifact's current location.
Gorion's Ward suspects that Bodhi has been entrusted with keeping the lanthorn from the elves and has most probably made off with it. Her lair in the catacombs underneath the Athkatla Graveyard would be a safe bet for her current refuge.
Elhan makes it clear that getting back the lanthorn from whomever stole it is a must do requirement. Only the lanthorn will allow a way to save the elven city and is necessary to put a stop to whatever Irenicus is plotting there. The party is to find the lanthorn and return it to the elven commander.
===Travel back to Athkatla===
When the party is ready to leave the Elven Temple at Underdark Exit area and travel, it is recommended to first head towards Athkatla. For best plot scripting results choose the Athkatla City Gates or Waukeen's Promenade as a travel destination. If playing with mods that added locations to the World Map, don't visit those at this time. The reason for this is that the scripting functions that trigger the Encounter - Drizzt Do'Urden may not initiate - and if it doesn't happen at this travel opportunity, then it will never occur later.
===Meet Drizzt Do'Urden===
Assuming the party was able to get the scripting to trigger when travelling for the first time upon leaving Elhan and the elves - the party will be "waylayed" with an encounter of Drizzt Do'Urden and his band of allies. See the link for what might transpire. 
This is an opportunity to potentially recruit some assistance in the upcoming conflict with Bodhi. It can also lead to hostilities, or it can just be a peaceful meeting where both the PC and Drizzt' part ways amicably. The choice rests mostly with the player and how they handle the discourse.
===Back in Athkatla===
When the party returns to the City of Coin the player can take care of various tasks as desired.
It's likely the party has much loot to dispose of and may need to restock supplies. Perhaps certain components found in Chapters 4 and 5 can be put to use with the master smith Cromwell in the Athkatla Docks. There may be some fresh gear and interesting items available from Ribald Barterman as well.
If the party is in the possession of the Silver Blade then moving through the Athkatla districts will trigger a surprise visit from the Githyanki Kruin. See his article page for details.
There may be open quests sill available for the party to finish off if they wish to do so before tackling Bodhi.
Elhan said that the party could seek allies in the confrontation with Bodhi, from various organizations the party had ties to before. This might mean that Aran Linvail could possibly be a worthwhile visit if the player previously sided with the Shadow Thieves against Bodhi.
Perhaps the various temple organizations might have some advice or provide help against the vampire coven as well. 
If the PC is a cleric and has a stronghold at one of the temples, then definitely explore this option if help is desired.
Don't travel to the Athkatla Graveyard until the party is ready to face Bodhi. The first visit to this district will trigger the event, and it is best done when the party is prepared and ready to do the task.
===Assault Bodhi===
When the party is prepared to undertake the task to face the vampire coven, travel to the graveyard district. Regardless of what time the party does this, it will be nighttime in the graveyard when the party arrives. 
Bodhi will intercept the party upon arrival there and initiate dialogue. The player won't be able to control the party or make any actions at all until the dialogue chain is finished. At this time the questline The final battle with Bodhi is registered in the player's journal. See that article for that part of the quest.
===Return the lanthorn===
Upon the defeat of Bodhi, the PC will have possession of the lanthorn and Bodhi's Black Heart.
If applicable, pursue the research and methods necessary to do something about one of the party being afflicted by vampirism, and pursue reviving the PC's lover.
When the player is ready to progress to Baldur's Gate II Chapter 7, travel back to speak with Elhan. He'll automatically know if the Rhynn lanthorn was found. Much dialogue will be shared.
During the conversation, Elhan makes mention that he knows that the murderous Bhodi had the lanthorn, which means he knows more than he was letting on before. More dialogue will take place about this, and the PC may be annoyed that Elhan won't give him the full story and background about what exactly Irenicus has against the elves. Elhan basically says that it is not for the party to know this - and mentions that Irenicus is referred to as "The Exile", and that he and Bhodi are deemed criminals by their society. 
Regardless of how persistent Gorion's Ward is to get additional info, Elhan refuses to share anymore, saying it is not his place to do so. He says that those involved in the city might be able to provide the answers, and to seek out Priestess Demin.
In the end, the party will be transported via teleportation to a section of the Forest of Tethir - the party and Elhan appear on a massive tree trunk sloping up to a stone cliff face.
Elhan is excited that the lanthorn is abuzz and is able to penetrate Irenicus wards - it will reveal a doorway which leads to Suldanessellar. 
Elhan says he must see the state of the city himself, and that the party should walk with reverence as one of the few outsiders to visit the place. 
He then enters the city and bids the party to follow when ready. The party then receives a large experience point reward for fulfilling the questline, to each party member.
When ready to do so, enter through the gateway.
When inside the city after a a cut scene, and a few conversations, this will officially closeout and finish The Elven City Requires My Aid questline - and registers the beginning of Chapter 7. 
Shortly after that a new quest entitled Getting Inside the Palace in Suldanessellar is added in the player's journal.