The guys are excited about building a “killer” robot named Monte for a regional robot fighting league when Kripke challenges them to a robot duel which Sheldon jumps at. The duel goes awry and Monte is the causality. Penny finally tells Wolowitz what she thinks of his crude behavior toward women and he is devastated by her comments; Leonard convinces her to go apologize. Just as she starts to sympathize, Wolowitz once again misreads the signs and Penny has a violent reaction.