Rift Quest:Drink Grengrug!  

It is advisable to attempt this quest when no one else is. Fighting for mugs can cause you to fail the 60 second time limit. There are six mugs inside the tavern and as soon as you fill one another will become active. Pay attention and always be looking for your next target and this quest should not give you too much trouble. Speak with Jacksen Winsley again to finish the quest.