By Michael Ausiello
December 05, 2008 at 09:26 PM EST

Here’s the story: Carol Brady’s headed to Samantha Who?!

Sources confirm to me exclusively that iconic Brady Bunch matriarch Florence Henderson has been tapped to play grandma to Christina Applegate’s title character this January.

Gram comes to town to help settle an argument between Sam’s mom (Jean Smart) and aunt (Christine Ebersole). As reported earlier this week, Auntie’s a little miffed because her sister used Sam’s amnesia as an opportunity to forget about her sibling’s existence.

Enter the peace keeping, conflict resolving machine that is one Mrs. Brady.