|the Cutthroat Banner of the Coin|
This quest is a sub-quest of Welcome to the Peacock Club and is initiated by examining the Service Entrance Key, Coin to the House of Coin. This key is dropped by a Palace Sweeper which spawns at ( -230, +160, -131 ) and then paths towards the arena. The Court the sweeper belongs to is random so you may have to go through a good number of them to get the correct key.
You zone into the Court of the Coin through the Service Entrance at the back of the building. It is a door, not a sewer grate as with the other two Courts. There're only 5 rooms in here, the main one, and 4 side rooms, one of which you zoned into.
Find the broken case that had the banner in it (it has been stolen), diagonally across from the entry point.
After getting this update move back to where you entered the Court, there will be 3 lvl 47vv Terrorantula Thief. Kill them quickly so that the guards don't path towards you (if you left any alive to begin with) and you get the banner and 9gp.
This quest has a 5 minute time limit.