The Loobenfeld Decay

The Loobenfeld Decay is the tenth episode of the first season of The Big Bang Theory.

Plot Summary
Leonard hears Penny singing and it is not good. When she asks them to come to a showcase Leonard lies and says that he and Sheldon have plans. Sheldon is uncomfortable with the lie which Leonard gives and so he comes up with a new one. Each time Penny believes him he finds new holes in his own lie and new ways to patch it up.

Extended Plot
Leonard enters the apartment building with Sheldon and tries to explain some irregularities in the Terminator show to him, the two of them suddenly hear terrible singing from the upper floors, they soon discover it was Penny who was singing terribly. Penny announces that she has landed the role of Mimi in the musical show; Rent. Upon hearing this, the two refused to go and Leonard makes a flimsy excuse about a symposium to avoid attending Penny's show and hurting her feelings. Sheldon is deeply disturbed as he feels Leonard's lie is full of holes and is easily seen through. So, the next morning Sheldon has conceived a new lie in which he tells Penny that Leonard lied because he wants to protect Sheldon from the embarrassment of having a drug addled cousin "Leopold Houston", which he made up. Additionally, Penny has agreed to act as if the original lie (Leonard's lie) was in play to avoid embarrassing Leonard. On the day of her show, Penny stops by at 4A to see Leonard and Sheldon before their intervention for Leopold at Long Beach, she acts as if they were attending the symposium, upon hearing that Howard and Raj has been left out of the symposium, Howard starts getting angry. Penny then asks Sheldon to reveal that they are not going to the symposium but rather an intervention, Penny then leaves for her show. After Penny leaves, Sheldon and Leonard tell Howard and Raj about the lie. After a discussion, they decide to go to Long Beach (where they were supposed to travel for the intervention) to see the Queen Mary. Later that night, Sheldon confronts a cranky Leonard (because he was woke up in the middle of the night) about the lie, he tells Leonard that there is a slight flaw. As Leonard is in no condition to talk, Sheldon decides to discuss the matter in the morning. The next morning, Leonard discovers a man eating cereal in his apartment, when questioned the man answered he was Sheldon's cousin; Leopold. Sheldon later clarified that the man was Toby Loobenfeld (Portrayed by DJ Qualls ), a research assistant at the University but he also minored in acting, this is why Sheldon enrolled his help to act as his drug addled cousin. Penny comes by to check how the intervention went, Sheldon tells her he has failed to convince Leopold to go to rehabilitation but was successful in getting him back to the apartment. Penny is introduced to Leopold, but soon it turned into an ugly fight as he and Sheldon disagree on the characteristics that Toby portrays. Penny then invites Leonard over to see a recording of her performance, he reluctantly agrees. Soon, Leopold begins to bond closely with Penny which disturbs Leonard.

Trivia

 * This is the first episode where Sheldon knocks a door 3 times,which would later be a recurring theme in the series. This time calls to "Leonard" and "Penny" However, the knock is 4 times in this episode.
 * Despite being described as a mysaphobe, Sheldon takes out the packed chicken he had previously threw in the garbage bin for consumption later, as he doesn't like waste as well.
 * There is QUEEN MARY merchandise in Leonard's room after they get back from the road trip.
 * Many parts of Toby's made-up background story could be refferencing "Hedwig and the Angry Inch". Such as loving somebody that betrays you, relations with older men, and gender ambiguity.

Critics
"The focus on one story gives the episode a clear structure and a memorable identity. It is both funny and plausible but is not a classic episode of comedy. The humour just isn’t strong enough to match the clever story." - The TV Critic's Review