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The Big Bang Theory S4E10 — The Alien Parasite Hypothesis
7.6
The Big Bang Theory•Season 4•Episode 10

The Alien Parasite Hypothesis

7.6/10 · 4,487 votesDec 9, 201020 min

Ranked #23 of 24 in Season 4•−0.4 vs season avg

Discussion

Amy finds she has sexual feelings for Penny's ex, while Koothrappali and Wolowitz try to prove who would be the better superhero.

Directed byMark Cendrowski
Previous episodeE9 · The Boyfriend ComplexityNext episodeE11 · The Justice League Recombination
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Season 4 Episodes24

The Robotic Manipulation stillE1 8.7

The Robotic Manipulation

The Cruciferous Vegetable Amplification stillE2 8.3

The Cruciferous Vegetable Amplification

The Zazzy Substitution stillE3 7.9

The Zazzy Substitution

The Hot Troll Deviation stillE4 8.0

The Hot Troll Deviation

The Desperation Emanation stillE5 7.6

The Desperation Emanation

The Irish Pub Formulation stillE6 8.0

The Irish Pub Formulation

The Apology Insufficiency stillE7 8.0

The Apology Insufficiency

The 21-Second Excitation stillE8 8.1

The 21-Second Excitation

The Boyfriend Complexity stillE9 8.4

The Boyfriend Complexity

The Alien Parasite Hypothesis stillE10 7.6Now viewing

The Alien Parasite Hypothesis

The Justice League Recombination stillE11 8.6

The Justice League Recombination

The Bus Pants Utilization stillE12 7.5

The Bus Pants Utilization

The Love Car Displacement stillE13 8.2

The Love Car Displacement

The Thespian Catalyst stillE14 7.7

The Thespian Catalyst

The Benefactor Factor stillE15 7.7

The Benefactor Factor

The Cohabitation Formulation stillE16 7.8

The Cohabitation Formulation

The Toast Derivation stillE17 7.9

The Toast Derivation

The Prestidigitation Approximation stillE18 8.1

The Prestidigitation Approximation

The Zarnecki Incursion stillE19 8.0

The Zarnecki Incursion

The Herb Garden Germination stillE20 8.2

The Herb Garden Germination

The Agreement Dissection stillE21 8.2

The Agreement Dissection

The Wildebeest Implementation stillE22 7.7

The Wildebeest Implementation

The Engagement Reaction stillE23 8.1

The Engagement Reaction

The Roommate Transmogrification stillE24 8.5

The Roommate Transmogrification

Cast7

Johnny Galecki

Johnny Galecki

Leonard Hofstadter

Jim Parsons

Jim Parsons

Sheldon Cooper

Kaley Cuoco

Kaley Cuoco

Penny

Simon Helberg

Simon Helberg

Howard Wolowitz

Kunal Nayyar

Kunal Nayyar

Rajesh Koothrappali

Melissa Rauch

Melissa Rauch

Bernadette Rostenkowski

Mayim Bialik

Mayim Bialik

Amy Farrah Fowler

Crew9

Chuck Lorre

Chuck Lorre

Story

Steven Molaro

Steven Molaro

Co-Executive Producer

Mark Cendrowski

Mark Cendrowski

Director

Jim Reynolds

Jim Reynolds

Teleplay

Steven Molaro

Steven Molaro

Story

Steve Holland

Steve Holland

Story

Maria Ferrari

Maria Ferrari

Teleplay

R

Robinson Green

Production Coordinator

Lee Aronsohn

Lee Aronsohn

Teleplay

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Episode Summary

"The Alien Parasite Hypothesis" is episode 10 of The Big Bang Theory season 4. It scored 7.6/10 from 4,487 votes, ranking #23 of 24 episodes this season (season average 8.0). Directed by Mark Cendrowski, it aired on December 9, 2010.

Next: E11 · The Justice League RecombinationBest of Season 4