4. Return to the pub and talk with the Drunken Cat, who rewards you with an UP Coin.
5. Move towards the group of snakes outside the pub (prontera 45, 73) and one of them will offer to exchange some Green Ale for the UP Coin.
Notes
Bathories are located on basement floor 4 of the Al De Baran Clock Tower, which a Key of Underground is required to access. The number of bathories has been slightly increased for the duration of the event.
Hunter Flies have been removed from level 1 of Geffen Dungeon & Poison Spore spawns have been increased for the duration of this event.
O'Riley will offer to warp you to the Clock Tower basement at no cost, once, if you have completed the quest once prior by using a Key of Underground.
The UP Coin has no other use outside of this quest.