Rumblings of a Grey's Anatomy flashback sequence featuring a young Richard and Ellis are well-documented at this point, and the ramifications are being hotly debated.

There are rumors that Jackson may be their love child, as Jesse Williams' character was deliberately cast as biracial, in contrast with the show's usual "blind" casting.

Now a new casting call for the episode indicates that Ellis and Richard won't be the only characters featured in this Grey's Anatomy blast from the dark, twisty past.

Take a look at who else we'll be seeing younger versions of (and what the ABC drama's casting agents require for whomever will portray them in the coming weeks):

[YOUNG THATCHER] Male, Caucasian, mid-late 20s, must look like actor Jeff Perry (below).

[YOUNG MEREDITH] Female, Caucasian, six-year-old to look and feel four years old.

Looks like Meredith's demons may be revealed as well as the Chief's ...

What do you think will happen in this Grey's Anatomy flashback?

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