Before Smallville takes a break for the holidays, it will give fans plenty to buzz over heading into 2011.

On December 3, John Glover will reprise his role as Lionel Luthor, making his first appearance on the show since being pushed out of a building to by son Lex three seasons ago. He'll appear on four episodes total.

From there, the mid-season finale will go down on December 10. It will feature Michael Shanks as Hawkman and Allison Mack as Chloe, making her first of four episode appearances.

"It is a great cliff-hanger going into the spring run, because there are a couple of pretty big twists in that episode," executive producer Brian Peterson tells TV Guide. "Things don't go very well for our heroes. Just when Clark is on top of the world, things kind of crash down around him."

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