Editor's note: This replaces the previously scheduled episode.

SHELDON TRIES TO KEEP HIS GEOLOGY COLLABORATION WITH BERT A SECRET, ON A REBROADCAST OF "THE BIG BANG THEORY," THURSDAY, FEB. 22

"The Geology Methodology" - Sheldon and Bert collaborate on a research project, despite Sheldon's embarrassment. Also, Penny and Bernadette coach Koothrappali on how to navigate his relationship with Ruchi (Swati Kapila)
, on a rebroadcast of THE BIG BANG THEORY, Thursday, Feb. 22 (9:00-9:30 PM, ET/PT) on the CBS Television Network. (Originally broadcast 11/9/17.)

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)
Brian Posehn (Bert)
Swati Kapila (Ruchi)

GUEST CAST:

Elka Rodriguez (Rose Lady)

STORY BY: Steve Holland, Anthony Del Broccolo, Adam Faberman

TELEPLAY BY: Eric Kaplan, Maria Ferrari, Tara Hernandez

DIRECTED BY: Mark Cendrowski