During a book reading, Amy tells Sheldon a piece of juicy gossip she heard where Bernadette is thinking about breaking up with Howard. Sheldon, in turn, shares with Leonard, who shares it with Priya who tells Leonard that it would be good news for Raj. He happens to have a crush on Bernadette. Leonard tells Penny about Raj's crush.
Later that day, in the cafeteria, Wolowitz, shares with the guys that he's thinking about asking Bernadette to marry him. That night, Sheldon tells Amy the news from Howard. The two of them decide to see how gossip moves through a social group. They plan to fabricate one juicy piece of gossip and a second, non-juicy piece, to use as a control.
Immediately, Amy seeks out Penny and tells her that she and Sheldon had intercourse! At the same time, she also tells her she's thinking of starting an herb garden.
When Penny runs into Raj later at the Cheesecake Factory, she sees him flirting with Bernadette and admonishes him for it. To get his mind off her, Penny shares the gossip about Sheldon and Amy. Back at the apartment, Leonard hints to Sheldon about what he heard. Sheldon realizes their false gossip appears to be spreading really fast. When the gang gets together for dinner, Wolowitz prepares to ask Bernadette to marry him but she jumps in by saying yes, surprising everyone.
Still unsatisfied, Amy later passes along two new bits of fake gossip to Penny: She's carrying Sheldon's child and she's taking bowling lessons.