Not sure, as I haven't followed through with it yet, but Aela (who I married in-game; doubt that matters though.) offers to let you regain the blood of the beast.
You get an "Are you ready?" dialog before setting off, but I plan on coming back to it when I'm done with DG. Unless that's a huge ruse, I imagine talking to the Companions, or in my case at least, Aela will get you started.