Season 4
🎬 24 Episodes 📅 2010 ⏱ 22 min
When an aspiring actress moves into the apartment next door, she inadvertently becomes the missing link in The Big Bang Theory's carefully constructed world of equations and comic books. Sheldon's rigid routines and Leonard's awkward charm collide head-on with her infectious energy, creating an unlikely dynamic that neither group expected. As Howard and Raj watch this clash of personalities unfold, they realize their insular circle might actually benefit from an outsider's perspective. What begins as neighborly annoyance transforms into genuine friendship, proving that sometimes the best connections happen when different worlds unexpectedly collide.
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📊 Season Stats
24
Episodes
2010
Year
22
min / ep
8.8
Watch Hours
4/12
Season No.
⭐ 8.0
Best Episode
Ep. 20 · The Herb Garden Germin…
🎬 Season Trailer
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🎬 Episodes 24 episodes
1
⭐ 7.9
The Robotic Manipulation
Penny tags along on Sheldon's first ever date; Wolowitz finds a new use for a robotic arm.
🎬 Mark Cendrowski ✍️ Chuck Lorre
2
⭐ 7.7
The Cruciferous Vegetable Amplification
Realizing he will not live long enough to download his consciousness into a robot body, Sheldon tries to extend his life span.
🎬 Mark Cendrowski ✍️ Bill Prady
3
⭐ 7.5
The Zazzy Substitution
The guys are concerned as Sheldon searches for an alternative to human companionship.
🎬 Mark Cendrowski ✍️ Chuck Lorre
4
⭐ 7.6
The Hot Troll Deviation
An embarrassing secret of Wolowitz's comes to light, while Sheldon and Raj have a small war at work.
🎬 Mark Cendrowski ✍️ Chuck Lorre
5
⭐ 7.4
The Desperation Emanation
Leonard realizes he’s the only one without a girlfriend, while Sheldon wants to get rid of his.
🎬 Mark Cendrowski ✍️ Bill Prady
6
⭐ 7.5
The Irish Pub Formulation
Leonard keeps an affair a secret from Sheldon, Howard and Raj.
🎬 Mark Cendrowski ✍️ Chuck Lorre
7
⭐ 7.6
The Apology Insufficiency
Sheldon's answers during an FBI interview put Wolowitz's security clearance in jeopardy.
🎬 Mark Cendrowski ✍️ Chuck Lorre
8
⭐ 7.8
The 21-Second Excitation
While the guys camp in line for a long-awaited movie screening, Penny and Bernadette invite Amy to her first slumber party.
🎬 Mark Cendrowski ✍️ Chuck Lorre
9
⭐ 7.9
The Boyfriend Complexity
Penny asks Leonard to lie to her father, while Howard, Raj and Bernadette pull an all-nighter at a telescope.
🎬 Mark Cendrowski ✍️ Chuck Lorre
10
⭐ 7.4
The Alien Parasite Hypothesis
Amy finds she has sexual feelings for Penny's ex, while Koothrappali and Wolowitz try to prove who would be the better superhero.
🎬 Mark Cendrowski ✍️ Chuck Lorre
11
⭐ 7.9
The Justice League Recombination
The guys find a "super" use for Penny's new boyfriend, Zack, when they enter a costume contest as the Justice League.
🎬 Mark Cendrowski ✍️ Chuck Lorre
12
⭐ 7.4
The Bus Pants Utilization
Leonard's idea for a smartphone app derails his friendship with Sheldon.
🎬 Mark Cendrowski ✍️ Chuck Lorre
13
⭐ 7.7
The Love Car Displacement
Bernadette runs into her ex-boyfriend while attending a science event with Wolowitz.
🎬 Anthony Rich ✍️ Chuck Lorre
14
⭐ 7.5
The Thespian Catalyst
Hoping it will make him a better teacher, Sheldon has Penny give him acting lessons. Raj has fantasies about a friend's girlfriend.
🎬 Mark Cendrowski ✍️ Chuck Lorre
15
⭐ 7.4
The Benefactor Factor
A wealthy donor to the university makes Leonard consider how far he's willing to go for the sake of science.
🎬 Mark Cendrowski ✍️ Bill Prady
16
⭐ 7.5
The Cohabitation Formulation
As Wolowitz contemplates taking things with Bernadette to the next level, Leonard rekindles his relationship with Raj's sister.
🎬 Mark Cendrowski ✍️ Chuck Lorre
17
⭐ 7.6
The Toast Derivation
Sheldon becomes concerned when everybody begins to hang out at Raj's apartment and discovers Leonard is the center of the group.
🎬 Mark Cendrowski ✍️ Maria Ferrari
18
⭐ 7.6
The Prestidigitation Approximation
Sheldon is baffled by Wolowitz's magic trick. Meanwhile, Leonard realizes dating Priya may make it impossible to continue being friends with Penny.
🎬 Mark Cendrowski ✍️ Bill Prady
19
⭐ 7.6
The Zarnecki Incursion
Sheldon's online-game account is hacked by Todd Zarnecki, who then proceeds to steal all his items prompting the guys to go on a quest to retrieve them. Penny, Bernadette and Amy discuss how Penny groomed Leonard to be willing to try various things and more adventurous boyfriend... for some other w…
🎬 Peter Chakos ✍️ Chuck Lorre
20
⭐ 8.0
The Herb Garden Germination
Sheldon and Amy decide to start several rumors about the others as a test. Meanwhile, Howard takes his relationship with Bernadette to even higher level.
🎬 Mark Cendrowski ✍️ Chuck Lorre
21
⭐ 7.3
The Agreement Dissection
When Leonard spends too much time in the shower with Priya, Sheldon charges Leonard with two violations of the roommate agreement. However, before he can get too far, Priya uses her skills as a lawyer to nullify the charges due to the agreement's vague wording, much to Sheldon's dismay. When the guy…
🎬 Mark Cendrowski ✍️ Bill Prady
22
⭐ 7.0
The Wildebeest Implementation
Raj attempts to cure his social anxiety disorder while Penny uses Bernadette to spy on Leonard and his girlfriend.
🎬 Mark Cendrowski ✍️ Chuck Lorre
23
⭐ 7.6
The Engagement Reaction
When Howard finally breaks the news to his mom that he's engaged to Bernadette, it lands her in the hospital.
🎬 Howard Murray ✍️ Eric Kaplan
24
⭐ 7.6
The Roommate Transmogrification
When Bernadette receives her PhD, Wolowitz feels emasculated. Raj and Leonard swap places and Penny does something she's regrets.
🎬 Mark Cendrowski ✍️ Chuck Lorre