Dishonored's second story-based expansion and is out next month, Bethesda has announced.

The Brigmore Witches concludes the story begun in The Knife of Dunwall, and is the final piece of DLC for Arkane Studios’ critically-acclaimed first-person action title.

The player’s power, weapon and item upgrades, Chaos level, and actions from The Knife of Dunwall will carry over via a compatible save file option.

The Brigmore Witches will contain previously unseen districts of Dunwall, and will be available for Xbox 360 and Windows PC on August 13, and PlayStation 3 on August 14.

Warning: spoilers for The Knife of Dunwall follow.

In The Brigmore Witches, the player continues his or her journey as Daud. After discovering the identity and intentions of Delilah, the leader of the Brigmore Witch coven, Daud sets out to disrupt her from completing a powerful ritual that will spell his doom.

Having already been betrayed by his lieutenant, Daud must rely on feuding gang factions – the Dead Eels and the Hatters – to negotiate his way through previously unseen districts of Dunwall en route to Delilah’s stronghold.

According to Bethesda, only one thing is for certain – that Daud will finally answer for his treacherous actions and fall before the mercy, or punishment, of the Royal Bodyguard and Assassin, Corvo Attano.

Final Dishonored add-on concludes Daud's story