11 Moments from The Big Bang Theory Episode 2

When Sheldon is forced to teach a class, Howard surprises everyone by taking it, on THE BIG BANG THEORY, Monday, Sept. 22, 2014 (8:30-9:00 PM, ET/PT), on the CBS Television Network. Pictured left to right: Simon Helberg, Jim Parsons, Kunal Nayyar and Johnny Galecki Photo: Michael Ansell/CBS ©2014 CBS Broadcasting, Inc. All Rights Reserved

When Sheldon (Jim Parsons, right) is forced to teach a class, Howard surprises everyone by taking it, on THE BIG BANG THEORY, Monday, Sept. 22, 2014 (8:30-9:00 PM, ET/PT), on the CBS Television Network. Regina King (left) Returns as Mrs. Davis Photo: Michael Ansell/Warner Bros. Entertainment Inc. © 2014 WBEI. All rights reserved.

When Sheldon is forced to teach a class, Howard (Simon Helberg, right) surprises everyone by taking it, on THE BIG BANG THEORY, Monday, Sept. 22, 2014 (8:30-9:00 PM, ET/PT), on the CBS Television Network. Regina King (left) Returns as Mrs. Davis Photo: Michael Ansell/Warner Bros. Entertainment Inc. © 2014 WBEI. All rights reserved.

When Sheldon is forced to teach a class, Howard surprises everyone by taking it. Meanwhile, the tension between Penny and Bernadette gives Amy a chance to play both sides, on THE BIG BANG THEORY, Monday, Sept. 22, 2014 (8:30-9:00 PM, ET/PT), on the CBS Television Network. Pictured left to right: Johnny Galecki, Kunal Nayyar, Simon Helberg, Mayim Bialik, Jim Parsons, Melissa Rauch and Kaley Cuoco-Sweeting Photo: Michael Ansell/CBS ©2014 CBS Broadcasting, Inc. All Rights Reserved

The tension between Penny (Kaley Cuoco-Sweeting, right) and Bernadette gives Amy (Mayim Bialik, left) a chance to play both sides, on THE BIG BANG THEORY, Monday, Sept. 22, 2014 (8:30-9:00 PM, ET/PT), on the CBS Television Network. Photo: Michael Ansell/CBS ©2014 CBS Broadcasting, Inc. All Rights Reserved

When Sheldon is forced to teach a class, Howard surprises everyone by taking it, on THE BIG BANG THEORY, Monday, Sept. 22, 2014 (8:30-9:00 PM, ET/PT), on the CBS Television Network. Pictured left to right: Simon Helberg, Kunal Nayyar, Johnny Galecki and Jim Parsons Photo: Michael Ansell/CBS ©2014 CBS Broadcasting, Inc. All Rights Reserved

When Sheldon (Jim Parsons, right) is forced to teach a class, Howard (Simon Helberg, left) surprises everyone by taking it, on THE BIG BANG THEORY, Monday, Sept. 22, 2014 (8:30-9:00 PM, ET/PT), on the CBS Television Network. Photo: Michael Ansell/CBS ©2014 CBS Broadcasting, Inc. All Rights Reserved

When Sheldon is forced to teach a class, Howard surprises everyone by taking it, on THE BIG BANG THEORY, Monday, Sept. 22, 2014 (8:30-9:00 PM, ET/PT), on the CBS Television Network. Pictured left to right: Johnny Galecki, Kunal Nayyar and Jim Parsons Photo: Michael Ansell/CBS ©2014 CBS Broadcasting, Inc. All Rights Reserved

When Sheldon is forced to teach a class, Howard surprises everyone by taking it, on THE BIG BANG THEORY, Monday, Sept. 22, 2014 (8:30-9:00 PM, ET/PT), on the CBS Television Network. Pictured left to right: Simon Helberg, Kunal Nayyar, Johnny Galecki and Jim Parsons Photo: Michael Ansell/CBS ©2014 CBS Broadcasting, Inc. All Rights Reserved

When Sheldon is forced to teach a class, Howard surprises everyone by taking it, on THE BIG BANG THEORY, Monday, Sept. 22, 2014 (8:30-9:00 PM, ET/PT), on the CBS Television Network. Pictured left to right: Simon Helberg, Kunal Nayyar, Johnny Galecki and Jim Parsons Photo: Michael Ansell/CBS ©2014 CBS Broadcasting, Inc. All Rights Reserved

The tension between Penny (Kaley Cuoco-Sweeting, left) and Bernadette (Melissa Rauch, right) gives Amy a chance to play both sides, on THE BIG BANG THEORY, Monday, Sept. 22, 2014 (8:30-9:00 PM, ET/PT), on the CBS Television Network. Photo: Michael Ansell/CBS ©2014 CBS Broadcasting, Inc. All Rights Reserved