The rumour mill was right; the next Hearthstone expansion is going to take players to the home of Medivh, Karazhan.

In the new adventure, One Night In Karazhan, players will be treated to a party of epic proportions in the Tower of Karazhan, a well known location in World Of Warcraft. The tower was once the location of opulent feasts and lavish parties before it was sealed following Medivh’s death.

Speaking at ChinaJoy to reveal the new adventure was Hearthstone Lead Designer Ben Brode.

“This is the first time that we’ve ever done a Hearthstone reveal in the People’s Republic of China,” said Brode.

“Look, you guys have been kicking butt recently, you dominated the Grand Tournament, you stopped Rafaram from stealing the Staff of Origination and you withstood the Whispers of the Old Gods, and now you’ve been invited to an exclusive one-night only event,” Brode said to fans both in attendance and watching in their droves around the world.

One Night in Karazhan takes on a rather fun atmosphere with disco music, pastel colours and a rather chirpy looking Medivh.

“We wondered what these places [Tower of Karazhan] looked like when they had people in them. Back when the most powerful archmage was also the most eligible bachelor,” explained Brode.

The adventure begins one hour before the party and Medivh is missing. It is up to players to destroy fight their way up the tower fighting various bosses to rescue Karazhan’s most elligible bachelor. We literally mean up the tower because unlike other adventures, players will start at the bottom of the adventure and move up, defeating bosses along the way.

Each boss defeated will unlock a new card for players to use in their decks.

Bosses include Barnes, who will require you to complete three “theater productions”, the Curator which will let loose the worst creatures imaginable.

Each of the bosses has a special power and some even have their own cards such as the Curator which will draw a Beast, a Dragon and a Murloc as its battlecry.

There will also be a free prologue for players to explore which will net them two cards. The first, Enchanted Raven is a 1-mana 2/2 beast for the Druid class. There is also a new mage spell. Firelands Portal will deal 5 damage and summon a random 5-mana minion.

One Night in Karazhan will feature 45 cards, 13 bosses and the first level will be released 11th August. New levels will be released each week after that and if you purchase the adventure in the first week you’ll get a “groovy” new card back.

And here we thought we were going to be saving some money this month.