Editor's note: The air time of this episode has changed.

AFTER SHELDON'S MOTHER AND LEONARD'S FATHER SHARE AN EVENING TOGETHER, EVERYONE DEALS WITH AN AWKWARD MORNING THE NEXT DAY, ON THE 10th SEASON PREMIERE OF "THE BIG BANG THEORY," MONDAY, SEPT. 19

Guest Stars Include Katey Sagal as Penny's Mother, Jack McBrayer as Penny's Brother and Dean Norris as Air Force Representative Colonel Williams Christine Baranski, Laurie Metcalf, Judd Hirsch and Keith Carradine Return

"The Conjugal Conjecture" - After Sheldon's mother and Leonard's father share an evening together, everyone deals with an awkward morning the next day. Also, Penny's family arrives for the wedding ceremony, including her anxiety-ridden mother, Susan (Katey Sagal)
, and her drug dealing brother, Randall (Jack McBrayer)
, on the 10th season premiere of THE BIG BANG THEORY, Monday, Sept. 19 (8:00-8:31 PM, ET/PT), on the CBS Television Network. Dean Norris guest stars as Colonel Williams, an Air Force Representative from the Department of Materiel Command. Christine Baranski, Laurie Metcalf, Judd Hirsch and Keith Carradine return.

REGULAR CAST:

Johnny Galecki (Leonard)
Jim Parsons (Sheldon)
Kaley Cuoco (Penny)
Simon Helberg (Wolowitz)
Kunal Nayyar (Koothrappali)
Mayim Bialik (Amy)
Melissa Rauch (Bernadette)

RECURRING CAST:

Kevin Sussman (Stuart)
Christine Baranski (Beverly)
Laurie Metcalf (Mary)
Judd Hirsch (Alfred)
Keith Carradine (Wyatt)
Katey Sagal (Susan)
Jack McBrayer (Randall)
Dean Norris (Colonel Williams)

STORY BY: Chuck Lorre, Steve Holland, Tara Hernandez

TELEPLAY BY: Steve Molaro, Eric Kaplan, Jim Reynolds

DIRECTED BY: Mark Cendrowski