It's based solely around companion NPC Leliana and her past with a criminal organization, with a unique reward unlocked once completed.
Leliana is the bard character that joins your Grey Warden troupe once you arrive at the first settlement after the 'incident' at Ostagar. DLC Leliana's Song will cost $7 when it releases but no date has yet been given by BioWare.
Once the high risk mission story is complete, which involves her mentor Marjolaine who can be 'dealt with' in Origins, you unlock a reward that carries over into the Origins main campaign and that of the Awakening expansion as well.
"Assume the role of Leliana, a young bard involved in a criminal ring that deals in political secrets. Accompanying her mentor Marjolaine on a high-risk mission, Leliana soon finds herself entangled in a game of intrigue that she cannot escape with just her beauty, charm, or stealth. The only way out of this game is to kill or be killed," say .
The last DLC for Dragon Age was the Darkspawn Chronicles which let you play out an alternate shorten version of the Origins campaign but as a Darkspawn hurlock vanguard commanding other Darkspawn on the battlefield.
Dragon Age: Origins released on Xbox 360, PS3 and PC.