From Bethesda Blog -
Those that have played Dishonored vividly can recall the actions of Daud – the legendary assassin that puts the game’s plot into motion. Beginning April 16th, you’ll return to this fateful moment and play the role of Daud in the story-driven add-on, The Knife of Dunwall.
Features of the new DLC include:
New Powers, Weapons and Gadgets – The mark of the Outsider empowers you with unique supernatural abilities. Call upon the Whalers to assist in combat with ‘Summon Assassin’, track down hidden Runes and Bone Charms with ‘Void Gaze’ and learn to use new variations to powers, including ‘Blink’. To aid in your dangerous exploits your customized arsenal of weapons and gadgets will include Chokedust to daze your enemies, whale oil powered Stun Mines to shock your targets, and a concealed Wristbow to launch sleep darts and explosive bolts.
Explore More of Dunwall –Make your way through the Legal District and infiltrate the Rothwild Slaughterhouse, a steaming factory filled with colossal whale carcasses and their hulking butchers. Revisit the decaying Flooded District, the location of Daud’s hidden base, first seen in the original game. Return to the scenes of key events in Dishonored with a new perspective, including the fateful moment that sets off Corvo’s journey.
Choose Your Path – On your search for answers, approach each mission with your own style. Your redemption – or your turn towards darkness – depends on your skills and the decisions you make. Discover the mystery behind Delilah in this stand-alone chapter, and then conclude Daud’s story in the upcoming final add-on, The Brigmore Witches.
The Knife of Dunwall will be available on April 16th on PlayStation 3 and Steam ($9.99), as well as on Xbox 360 for 800 Microsoft points. Stay tuned for new information on the content.