[s2e12] The Killer Robot Instability -

: This is the first time Howard's mother speaks without shouting. Production Credits Director Mark Cendrowski Writers Bill Prady, Richard Rosenstock, Steven Molaro, Daley Haggar Starring

is the twelfth episode of the second season of The Big Bang Theory , first aired on January 12, 2009. The episode follows two primary storylines: the guys' participation in a cutthroat robot fighting competition and a major emotional confrontation between Howard Wolowitz and Penny . Plot Overview [S2E12] The Killer Robot Instability

Johnny Galecki, Jim Parsons, Kaley Cuoco, Simon Helberg, Kunal Nayyar : This is the first time Howard's mother

S 2 E 12 The Killer Robot Instability Analysis. : r/bigbangtheory Plot Overview Johnny Galecki, Jim Parsons, Kaley Cuoco,

: Leonard guilt-trips Penny into apologizing to Howard. When she does, Howard attempts to take advantage of her kindness by going in for a kiss, leading Penny to punch him in the face. Notable Firsts and Trivia

: This episode marks the first appearance of Barry Kripke , played by John Ross Bowie .