Time to dust off those brain tumor rumors: Katherine Heigl is seeing dead people again on Grey's Anatomy.

For the second time this season, Jeffrey Dean Morgan's deceased Denny will descend from heaven to have a heart-to-heart with his Earth-bound soul mate, Izzie, sources confirm to me exclusively. ABC declined to comment, but my Grey's mole says Morgan will appear in the Nov. 6 episode.

What brings Denny back this time? I could tell you, but then Shonda Rhimes would kill me and, well, you'd all be up scoop's creek. Instead, I'll leave you with this tantalizing clue: Something happens in the episode that could easily set the stage for a Heigl departure at season's end. I'm not saying it will; only that it could.

Think you got it figured out? The comments section is currently accepting your theories.