Time to dust off those brain tumor rumors, writes Michael Ausiello of EW: Katherine Heigl is going to be 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 soul mate, Izzie.

ABC declined to comment on the subject, but a Grey's Anatomy mole says that Jeffrey Dean Morgan will appear in the November 6 episode, "Rise Up."

What brings Denny back this time? Here's a 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.

What do you think it could be?

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.