This quest became available for me when I had 8000/12000 honored rep with The Nightfallen.
Quest leads to:
1a. Either With Us - Speak to Lady Aurore which is located in 'The Gilded Market'. (Location)
1b. Thinly Veiled Threats - Rescue Ailen. (Location)
1c. Vote of Confidence - Quest turn in is with Ly'leth at Warning Cresent.
2a. Or Against Us - Speak to Arluin. Requires 1200 [currency=1155]. (Location)
2b. Death Becomes Him - Requires you to kill [npc=110365] which is located in 'The Gilded Market'. (Location)
2c. Rumor Has It - I recommend checking out Annalisse's comment on the quest page. It's helpful to completing this quest. Quest turn in is with Ly'leth at Warning Cresent.
Requires quests 1C&2C done:
3. In the Bag - Located at 'The Grand Promenade'. To quickly get here, use the teleport from Warning Cresent to Shal'Aran and then take the portal to the Sanctum of Order.
3a. Ly'leth's Champion - Talk to Ly'leth to start the encounter. Complete quest to get send back to the tavern.
Completes Statecraft for Good Suramaritan
4. Friends With Benefits - Return to Thalyssra, located at Meredil.
4a. Court of Stars: Beware the Fury of a Patient Elf - Enter the Court of Stars dungeon. Slay Advisor Melandrus and collect his Spellstone. Return to Thalyssra on completion. (Reward: [item=140421])
4b. The Arcway: Opening the Arcway - Enter the Arcway dungeon. Slay Advisor Vandros. Return to Thalyssra on complection. (Reward: [item=140409])
4c. The Arcway: Long Buried Knowledge - Enter the Arcway dungeon. Loot the Suramar Leyline Map. This quest is available from Arcanist Valtrois, who's down at the leyline feed.
The Court of Stars and Arcway dungeon are only available on Mythic and Mythic+ difficulty.