Elder Scrolls Online developer ZeniMax Online plans to begin offering new DLC packs quarterly, and among those on the way are ones adding the Dark Brotherhood and Thieves Guild.

During an ESO panel at QuakeCon, ZeniMax revealed more about its plans for handling DLC. The recently announced Imperial City pack and its accompanying patch will be available to those playing on public test servers next week, followed by their full PC/Mac launch on August 31. (Xbox One and PS4 get the DLC on September 15.) ZeniMax will follow this up with the Orsinium pack sometime this fall, which introduces the titular city and is said to consist of around 25 hours of new content.

More exciting is what’s planned for next year. The Dark Brotherhood and Thieves Guild, which tend to be responsible for the most entertaining quests in the single-player Elder Scrolls games, will both be added in the first half of 2016. Each of the two will be available in its own DLC pack; there was no word on which will come first or what exactly they’ll consist of.

Pricing for ESO’s DLC has not been announced, save for the Imperial City pack, which is priced at $20 or is included with an ESO Plus subscription. These types of expansions are likely to be the norm going forward in light of Bethesda’s decision to drop ESO’s subscription.

The Elder Scrolls Online launched on PC last year, but has since seen major updates (including the abandoning of its monthly subscription). The long-delayed Xbox One and PS4 versions launched in June.