A surprise hits Penny and Leonard hard. One drunken night changes Sheldon and Amy's relationship paradigm. Bernadette gets some news she isn't sure how to handle. Raj falls for a new girl, who has a surprising connection to one of his friends. All of this was unintended, but after all, science teaches you that when things go bad, you don't give up. You adapt. LP, SA, HB, ROC.