The Monopolar Expedition

The Monopolar Expedition is the twenty-third and final episode of the second season of the CBS sitcom, The Big Bang Theory. This episode first aired on May 11, 2009.

Summary
The guys are going to the North Pole to assist Sheldon looking for data to prove String Theory making both Penny and Leonard upset about being apart for three months.

Extended Plot
After Sheldon wakes up the president of Caltech in the middle of the night simply to ask a question, he is offered to spend three months doing research on the North Pole in an attempt to prove the validity of string theory. Leonard, Howard and Raj are overjoyed, since this will make them able to do things which Sheldon doesn't usually allow, like sitting on his side of the couch, but when offered to go with him, they reluctantly agree; Raj because he believes that if he suffers that much, he will be reincarnated as a "well-hung billionaire with wings" and Wolowitz because he could become "the engineer who designs the cross-bow that kills Sheldon " (as well as because of peer pressure). Leonard however shows some doubt as the trip will mean that he won't see Penny for the whole summer. Penny seems upset when she learns that he will be away and did not mention it to her. She later gives him a blanket with sleeves and a long hug. Leonard becomes confused about what happened, and seeks advice from Sheldon later that night. Sheldon says that the long hug means that on some level, Penny wants Leonard Once he realizes what he just said to Leonard, he takes it back. The next morning, Leonard asks what it all meant. Penny claims that the wishes, blanket and hug were to simply wish him a safe trip, but after he closes the door, it turns out that Sheldon 's instincts were correct, as she whispers "It means I wish you weren't going". At the North Pole, the quartet settle into a cabin similar in outlining to Sheldon and Leonard's apartment , watch Ice Station Zebraand John Carpenter's The Thing (both of which take place in polar climate) and eat reconstituted Thai food. Howard kids with Raj "There's no time for a crossbow, find me an icicle".

Critics
"The Leonard and Penny relationship has been on the back burner all season and so this low key acknowledgement of her feelings felt appropriate. The show is probably going to be around for years to come so the producers are in no hurry to change the dynamics of the group yet...Instead of that scene we could have been exploring how Leonard and Penny feel about each other and why. Again there are so many simple things which the show could do to help build their relationship up as a more realistic entity...This episode sums up the whole of season two of the show. It’s too reliant on Sheldon, not focussed on character development and too static for my tastes. On the flip side it is also funny, consistent and showcases a genuinely strong comic character." - The TV Critic's Review

Quotes

 * Penny: Leonard, I don't know what to tell you; it was just a hug.
 * Leonard: Glad we cleared that up.
 * Penny: Yeah.
 * Leonard: I guess I'll see you.
 * Penny: OK, have a safe trip.
 * Leonard: Thank you. Bye.
 * Penny: Bye. [closes her door and sighs] It means I wish you weren't going.

Trivia

 * When Sheldon says "logic dictates," he mimics Spock's words, memorably stated in Star Trek II: The Wrath of Khan and the Star Trek episode The Savage Curtain. Similarly, in The Bat Jar Conjecture, he purports, "No man should be forced to emblazon his chest with the bengal tiger, when common sense dictates it should be an army ant."
 * Penny again can't tell Leonard how she feels about him.

Critics
"This episode sums up the whole of season two of the show. It’s too reliant on Sheldon, not focused on character development and too static for my tastes. On the flip side it is also funny, consistent and showcases a genuinely strong comic character." - The TV Critic's Review