Air Date	:	2011-01-20
Season Number	:	4
Genres	:	Comedy
Storyline	:	Bernadette runs into her ex-boyfriend while attending a science event with Wolowitz.
Casts	:	Johnny Galecki (Leonard Hofstadter), Jim Parsons (Sheldon Cooper), Kaley Cuoco (Penny), Simon Helberg (Howard Wolowitz), Kunal Nayyar (Rajesh Koothrappali), Melissa Rauch (Bernadette Rostenkowski), Mayim Bialik (Amy Farrah Fowler),