Wolowitz is in charge of the kids while Bernadette and Penny are in San Diego for a pharmaceutical sales convention; Amy and the guys experiment on the kids when Sheldon finds a book on it.

Cast: Johnny Galecki, Jim Parsons, Kaley Cuoco, Simon Helberg, Kunal Nayyar, Mayim Bialik, Melissa Rauch, Kevin Sussman, Pamela Adlon, Chasty Ballesteros, Christine Baranski, Andre Boyer, Jason Kravits, Ben Rauch