Beginning on October 23, the Shadow of the Mad King event returns for nearly two weeks of ghoulish capers, spooky fights, and holiday fun! Get ready for another year of tricks, treats, and terrible jokes as the pumpkin-headed former ruler of the Thorn dynasty graces Lion’s Arch with his presence. One more thing, the Mad King Lair RETURNS!! This event hasn't been seen since 2012, where you do battle with the Mad King!Read More:
https://www.guildwars2.com/en/the-game/releases/october-23-2015/