The newest expansion for The Elder Scrolls Online, called Dark Brotherhood, has been announced and will be arriving May 31st on the PC before being released on the Xbox One and PlayStation 4 on June 14th.
This expansion will return to he Gold Coast, which was last seen in The Elder Scrolls IV: Oblivion in 2006. In the new expansion you'll be able join the Dark Brotherhood and "Become the deadliest assassin with a new and exclusive passive skill-line, defend the Brotherhood against a mysterious foe in hours of new story content, prove your skill for homicide in new repeatable assassination quests, and more," or so says the description. It sounds as if there should be a fair amount of story content for those that have wanted more than just bare quests as an excuse to play with friends. It's a return to form, more than that, it's a further exploration of deep narrative that surrounded one of the best and most interesting organizations in the games lore.
The base game itself is getting a sizable patch to coincide with Dark Brotherhood that is going to remove the Veteran Ranks and the addition of poison making, among all sorts of other gameplay and combat balances that have been made.
The next expansion will be free for those that have an ESO Plus membership, which costs $15/month, but it can be purchased separately for 2,000 Crowns, the in-game currency, which costs around $12. You can buy packs of 750 crowns for $8, 1,500 crowns for $25.