<P> `` The Recombination Hypothesis '' is first episode of a two episode arc featuring Leonard and Penny attempting to restart their relationship that has been one of the major plot lines and driving forces of the series . The arc concludes with the next episode `` The Beta Test Initiation '' where Penny and Leonard return from their date . The first scene is a salute to the original pilot where Leonard and Sheldon climb the stairs wearing similar outfits and they spot Penny through her apartment door wearing the same shirt from the pilot . Sheldon is disappointed to discover that a Mr. Spock cardboard stand - up he ordered is a portrayal of Zachary Quinto 's Spock not Leonard Nimoy 's Spock . According to Bill Prady , the co-creator of The Big Bang Theory , approval from Paramount , J.J. Abrams ( producer of the new Star Trek series ) and Zachary Quinto was required in order to mock Spock . Also , this is the first time that an entire episode is a `` dream - sequence '' , a unique style of storytelling , and is the second Chuck Lorre show to achieve the `` dream - sequence '' story , after Two and a Half Men in the episode `` Frodo 's Headshots '' . </P>
<P> `` The Recombination Hypothesis '' is first episode of a two episode arc featuring Leonard and Penny attempting to restart their relationship that has been one of the major plot lines and driving forces of the series . The arc concludes with the next episode `` The Beta Test Initiation '' where Penny and Leonard return from their date . The first scene is a salute to the original pilot where Leonard and Sheldon climb the stairs wearing similar outfits and they spot Penny through her apartment door wearing the same shirt from the pilot . Sheldon is disappointed to discover that a Mr. Spock cardboard stand - up he ordered is a portrayal of Zachary Quinto 's Spock not Leonard Nimoy 's Spock . According to Bill Prady , the co-creator of The Big Bang Theory , approval from Paramount , J.J. Abrams ( producer of the new Star Trek series ) and Zachary Quinto was required in order to mock Spock . Also , this is the first time that an entire episode is a `` dream - sequence '' , a unique style of storytelling , and is the second Chuck Lorre show to achieve the `` dream - sequence '' story , after Two and a Half Men in the episode `` Frodo 's Headshots '' . </P>
when do penny and leonard first get together
when do penny and leonard first get together
The Recombination Hypothesis
The Recombination Hypothesis