The Justice League Recombination

The Justice League Recombination is the eleventh episode of the fourth season of the CBS sitcom, The Big Bang Theory. This episode first aired on December 16, 2010.

Summary
The guys get Zack and Penny to join their Justice League costume group for a New Year's Eve bash at the comic book store to win the best group costume prize.

Extended Plot
The guys discover that Penny and her ex-boyfriend, Zack, are back together and they take advantage of his lack of intelligence and make fun of him. After Zack finally realizes what's going on and storms out, the guys decide to apologize to him and give him some Milk Duds. Zack immediately forgives Leonard and his friends and goes with the guys to the comic book store, leaving Penny behind. At the store, the guys realize tha tZack would be great as Superman for their Justice League group at Stuart 's New Year's Eve costume party, which would replace Leonard as that role.

Leonard agrees as long as he goes as Green Lantern, leaving Raj to be Aquaman, much to his dismay. They return home with the Justice League costumes, with Howard being Batman, Raj as Aquaman, Sheldon as The Flash, and Leonard as Green Lantern. They even purchase a Wonder Woman costume for Penny. However, Penny doesn't want to go and suggests that they ask Bernadette or Amy, but Howard says Bernadette is under quarantine and Sheldon says Amy doesn't believe in wearing costumes, leaving no choice but for Penny to go. On the night of the party, the guys arrive at the apartment in their costumes. Sheldon as the Flash is pacing back and forth though Leonard say that it looks like he's jogging. Sheldon replied by saying, "This is how The Flash paces". But Penny refuses to wear the black wig and eventually refuses to even go to the New Year's Eve costume party at the comic book store. None of the guys, not even Zack, can convince Penny to go. Since Zack would not go without Penny and theJustice Leaguewouldn't be complete without Superman and Wonder Woman, Sheldon says that they'll have to go in their Muppet baby costumes but then they make Leonard talk to Penny. Penny reveals that she is only with Zack because she doesn't want to be alone for New Year's Eve. It is hinted that she still hasn't fully gotten over Leonard. Penny relents, puts the wig on to avoid the "Leonard " question, and the group later wins the costume contest. When midnight strikes and it becomes 2011, Zack is kissing Penny, she looks guiltily over at Leonard for the duration of the entire kiss. The episode concludes with the group witnessing an ongoing car theft on the way back home and despite wearing Justice League costumes, they comically scurry off, none of them, not even Zack, are brave enough to stop the car theft. That New Year's Day evening, Leonard warns Sheldon that he wants to change the thermostat temperature. Sheldon then imagines himself as The Flash, speeding to the Grand Canyon to scream in frustration. Once he is finished, Sheldon tells Leonard, "Fine".

Critics
"This failed on pretty much every level which was a shame. In theory I applaud the idea of focussing on Penny and Leonard's relationship but there is no authenticity to it anymore. The writers have made less and less effort to demonstrate any actual bond between them. Leonard still treats her like she is too good for him and her feelings for him have returned out of nowhere. The result is that her emotions seem fabricated and the story falls flat...What often saves The Big Bang Theory from being a lame duck is the sharpness of its writing. In this case the writing was lazy and the result was a lousy episode which felt as phoned in as Penny 's feelings for Leonard ." - The TV Critic's Review

Quotes

 * Zack: Hold on. The costume came with a black wig. Where is it, babe?
 * Penny: No. I'm not wearing it. It looks stupid.
 * Zack: Come on. We're trying to win a contest here.
 * Penny: Forget it. I'm not wearing the wig.
 * Zack: Penny. There's no I in Justice League.
 * Howard: Well, actually.
 * Sheldon: Don't. He's making our case.

Trivia

 * The Justice League consists of
 * Sheldon as: The Flash
 * Leonard as: Green Lantern
 * Howard as: Batman
 * Penny as: Wonder Woman
 * Zack as: Superman
 * Raj as: The Aquaman
 * Sheldon asks in what universe is Wonder Woman blonde, in fact Cathy Lee Crosby starred as a blonde Wonder Woman in the unsuccessful 1974 TV movie "Wonder Woman " Also in a Teen Titans storyline "Titans Tomorrow" Cassandra Sandsmark aka Wonder Girl, who was a blonde, was shown as Wonder Woman' s successor.Iwuiwwb.jpg
 * Raj once went to a cricket camp, and had a penis drawn on his face by bullies there.
 * Stuart reveals that he earns around $1.65 an hour, $6.35 below the minimum wage in Pasadena, California though Stuart owns the stores and that is based upon the long hours he puts in and not a salary.
 * Raj reveals he hates Aquaman in this episode. In The Spaghetti Catalyst, Raj stated, "Oh, please, we all know I’m the friend you call when you have no other options. If we were the Justice League, I’d be Aquaman ." He also mentioned Aquaman in The Precious Fragmentation and The Robotic Manipulation.
 * Some species of sea star have the ability to regenerate lost arms and can regrow an entire new arm in time. Sea stars can grow an entire sea star from a single ray.
 * Bernadette is apparently under quarantine for this episode, as at her lab Christmas party she took jello shots from a petri dish that used to contain Yellow Fever. This was revealed by Howard when the guys asked why she couldn't be Wonder Woman.
 * At the costume party, Stuart is dressed as Tom Baker's Doctor from the BBC series Doctor Who.
 * When Penny is talking to Leonard in her apartment, this is the closest that she ever comes (at this point) to telling Leonard how much she feels for him. Penny refers to The Middle Earth Paradigm when she states to Leonard, "Look, if Zack and I had just gone to a regular club or a party, it would have been fine, but this, with the costumes, and you."
 * The costumes the cast choose reflects their character:


 * ​Howard as Batman : Howard is an engineer and has built a lot of high-tech gadgets, such as an engineer might make.
 * Raj as Aquaman : In comic books Aquaman is the King Of Atlantis and spends a lot of time being classified as an outsider. Raj as a foreigner sometimes doesn't understand American culture and is an outsider in other ways.
 * Penny as Wonder-Woman : Fairly self explanatory.
 * Leonard as Green Lantern : Green Lantern is a character who uses a ring to create constructs using their will. Green Lantern users therefore must have a lot of will to be succesful. Obviously Leonard  has the will to work hard in his studies to become a Doctor. What is relavent though is that Leonard must have great will to put up with Sheldon.