Raj and Sheldon try to simulate a dark-matter research expedition; after a fight about money, Penny and Leonard turn to Bernadette and Wolowitz for advice.
Director:
Mark Cendrowski
Cast:
Johnny Galecki
Jim Parsons
Kaley Cuoco-Sweeting
Simon Helberg
Kunal Nayyar
Mayim Bialik
Melissa Rauch