Almost all Smash viewers seem to be in agreement: this NBC drama is at its best when the focus is on the production of its play, not the personal lives of the characters behind it. That point was driven home again on this week's "Hell on Earth."

So let's all hope that's the direction in which we're headed going forward this season, with the show - and the show within the show - taking the major step of bringing in an established star to play Marilyn next Monday... Uma Thurman!

Watch the official promo for her arrival below and also prepare for Derek to test how much pressure Karen can withstand as an understudy, while Tom and Julia celebrate their anniversary on the episode.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.