The Big Bang Theory (2007–2019)
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The Clean Room Infiltration 

1:05 | Trailer
Amy hosts a traditional Victorian Christmas Eve dinner as Raj's father comes to visit, while the guys try to shoo out a bird they let into the university clean room.


Mark Cendrowski


Chuck Lorre (created by), Bill Prady (created by) | 8 more credits »





Episode complete credited cast:
Johnny Galecki ... Leonard Hofstadter
Jim Parsons ... Sheldon Cooper
Kaley Cuoco ... Penny (as Kaley Cuoco-Sweeting)
Simon Helberg ... Howard Wolowitz
Kunal Nayyar ... Raj Koothrappali
Mayim Bialik ... Amy Farrah Fowler
Melissa Rauch ... Bernadette Rostenkowski
Brian George ... Dr. V.M. Koothrappali
Dakin Matthews ... Santa
Michael Reetz ... Photographer


Raj can't host this year's Christmas Eve dinner party because his soon to be divorced father is coming for a visit. So Amy volunteers to host the dinner, she choosing the theme of a traditional Victorian Christmas. Raj and Dr. Koothrappali are nonetheless invited. The day of the party, Leonard and Howard, working on an experiment in the clean room, are detained and require Raj's help when an accident causes the clean room to be not so clean. They have to figure out what to do, the three ultimately deciding that the blame falls on one person, who has a sense of déjà vu for the remainder of the evening and as they deal with the issue. Bernadette is driving Sheldon to Amy's. Irked that Amy would agree to host a dinner that he wants no part of, Sheldon tries to figure out a way to get back at Amy. That leaves Amy, Penny and Dr. Koothrappali alone at the party, which is dominated by Dr. Koothrappali's less than positive current view of marriage, and Amy's focus on making everything as ... Written by Huggo

Plot Summary | Plot Synopsis


Comedy | Romance


TV-PG | See all certifications »






Release Date:

11 December 2014 (USA) See more »

Company Credits

Show more on IMDbPro »

Technical Specs


Sound Mix:




Aspect Ratio:

16:9 HD
See full technical specs »

Did You Know?


It's a Christmas themed episode. See more »


Besides not being properly dressed for the clean room (no masks, gloves), there is a problem with the clean room. Clean rooms are overpressurized. The air pressure in the room is slightly greater than outside because it helps keep the dust out. You can't overpressurize a room if hanging plastic/vinyl slats acts as your door. And you need to pass through an air shower, after you are suited up, to enter a clean room. You open a door, walk in, the door closes, the shower starts and when it is finished the opposite door opens allowing entry to the clean room. Exiting happens in reverse. The 2 doors are never open at the same time. So, even if a dock door was left open, there is no possible way for a bird (or 2) to fly into a clean room. See more »


Amy Farrah Fowler: I've always wanted to do a traditional Victorian Christmas: parlor games, goose, and figgy pudding...
Sheldon Cooper: Yuck! English pudding! You get yourself all excited for pudding, and here comes a cake with raisins in it. I'm not going.
Amy Farrah Fowler: You're going.
Sheldon Cooper: Why do you hate me?
Amy Farrah Fowler: I don't hate you, I love you.
Sheldon Cooper: Well, you call it "love", but it has a lot of raisins in it.
See more »

Crazy Credits


As I mentioned a few episodes ago, I'm no longer writing vanity cards. Going forward I plan on experimenting with different ideas to replace them. The next two can be seen following tonight's episodes of Mom and Two and a Half Men. I'd very much like to get your input before I make a final decision. Perhaps we can have some sort of online vote. Of course those of you who follow the cards hoping to find something to hate are certainly welcome to continue on in that manner. See more »


References Two and a Half Men (2003) See more »


History of Everything
Written by Barenaked Ladies
Performed by Barenaked Ladies
[Series theme song played during the opening titles]
See more »

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User Reviews

One of season 8 best episodes
11 December 2014 | by ycare591See all my reviews

People have been saying that The Big Bang Theory has been declining. But this episode proves that people are wrong and that the show is still fun to watch. This was an amazing and funny episode. All the characters were good. We were even able to meet a new character. Jim Parsons was amazing as always. I hope there are more episodes like this. A pretty fun episode. This show is still not dead. This episode of the big bang theory was a 10/10. I hope the following episodes will be just as good. It was probably as good as last years episode of the Thanksgiving one. And that's all I have to say. Nothing more, nothing less.

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