The Clean Room Infiltration Season 8, Episode 11 -  Aired December 11, 2014

The Clean Room Infiltration

Leonard and Howard are performing an experiment in the university clean room, but when they accidentally let a bird in they need Raj's help. Meanwhile, as Amy hosts an authentic Victorian Christmas party, Sheldon resents her forcing him to celebrate the holidays and shops for the perfect gift to ruin Christmas.

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Guest Stars: Brian George as Dr. Koothrappali, Dakin Matthews as Santa

Writers: Maria Ferrari (Story), Tara Hernandez (Story), Jeremy Howe (Story), Eric Kaplan (Teleplay), Jim Reynolds (Teleplay), Steve Holland (Teleplay)

Director: Mark Cendrowski

Viewers: 15.49 million Adults 18-49 Rating: 3.9/13

Available on iTunes

Episode Lists

  • Christmas Episodes Christmas Episodes

    Celebrate Christmas with Sheldon, Leonard, Penny, Howard, Raj, Amy and Bernadette in these classic Christmas episodes of The Big Bang Theory.

Episode Notes

  • The title simply refers to the pigeon flying into the university clean room where Leonard and Howard were working.

Episode Quotes

Raj: Amy, good luck getting these guys excited about a dinner with a theme. I gave up when no one cared about my Tom Hanks-Giving.

Sheldon: Let's see. What do I know about Amy? She loves medieval literature. Chaucer's her favorite. And her eyes sparkle when she watches old French movies. And I enjoy how harp music causes her fingers to dance as if she's playing along.
Bernadette: Wow, you really do love her.
Sheldon: I do. Now, let's find the kind of gift that makes her feel small and worthless.

Santa: All right, let me see if I've got this straight. A picture of you on my lap is a way to punish your girlfriend for making you celebrate Christmas?
Sheldon: Correct.
Santa: Santa thinks dating you might be punishment enough.
Sheldon: There's an argument for that, but I want to make sure.

Bernadette: Why'd you turn it off?
Sheldon: Because in the last ten minutes, Santa came to town, kissed mommy, and ran grandma over with a reindeer. I had a drunk uncle who did all those things. Nobody sings songs about him.

Amy: Well, you got me something. Here.
Sheldon: Cookies?
Amy: They're your MeeMaw's Christmas cookies. I called and got the recipe.
Sheldon: They're perfect. It tastes like her hugs.
Amy: Merry Christmas, Sheldon.
Sheldon: I can't believe this. You're happy. I'm happy. Maybe a holiday that's all about giving isn't so - Get your hand out of that box!

News Stories

Title Date Posted
811 'The Clean Room Infiltration Ratings' December 12, 2014

Yesterday's The Big Bang Theory was the most-watched and highest-rated program of the night. With ABC running The Taste in place Grey's Anatomy, The Big Bang Theory had more viewers than the four competing programs combined.  Full story

811 'The Clean Room Infiltration' Pictures December 6, 2014

Pictures from the next episode of The Big Bang Theory, "The Clean Room Infiltration", have been added to our gallery. The Christmas-themed episode air this Thursday, December 11. Check out thumbnails of the pictures below and head over to our gallery to view all the full-sized pictures from the holiday episode.  Full story

811 'The Clean Room Infiltration' Press Release November 24, 2014

CBS has put out the press release for the next episode of The Big Bang Theory, "The Clean Room Infiltration", which will air Thursday, December 11.  Full story


As the group gathers to decorate the Christmas tree, Raj mentions how his newly divorced father will be in town soon and as a result he won't be able to host the annual Christmas eve dinner. Amy volunteers to host the dinner this year as she's always wanted to host a traditional Victorian Christmas party.

Leonard and Howard are in the university clean room, finishing up after their experiment and getting ready to attend Amy's Christmas dinner when a bird flies in. Howard doesn't want to call building facilities as they will get blamed. In Amy's apartment, Amy and Penny are chatting with Raj and his dad, who has nothing good to say about marriage or his ex-wife. Leonard and Howard call for Raj's help in dealing with the avian intruder. Elsewhere, Bernadette is driving Sheldon to the mall so he can find a present for Amy. Resentful at being made to celebrate Christmas, Sheldon wants to buy a Christmas gift for Amy as they agreed not to buy gifts and she won't have a present for him, ruining her Christmas.

Back in the clean room, Raj arrives just as Howard is trying to catch the pigeon in a garbage bag with a Slim Jim. When Howard holds the Slim Jim up, the bird swoops in and gets it, avoiding the garbage bag. Back at Amy's apartment, Dr. Koothrappali thinks it's too soon for him to start dating again. Amy gets the party started with a game that involves blowing a ball of wool across a table. Howard and Leonard start arguing in the clean room.

Bernadette and Sheldon arrive at the mall in search of a gift to ruin Amy's Christmas. Bernadette says Howard's best gifts were inspired by what Howard knew about her. Sheldon knows Amy likes Chaucer, medieval literature and old French movies, and he likes the way her fingers dance around whenever she hears harp music. Sheldon admits he really does love Amy - and wants to find a gift to make her feel small and worthless. In Amy's apartment, Dr. Koothrappali wins the ball of wool game. When Dr. Koothrappali remembers the theme parties his wife used to throw, Penny suggests that's where Raj gets his interest in being a host.

Back at the mall, Sheldon is sitting on Santa's lap to get a photo as a punishment for Amy. Santa suggests dating Sheldon is punishment enough, which Sheldon accepts but he still wants the photo to be sure. In the clean room, the guys are using a blanket and a fire extinguisher to shoo the bird out the door. When Howard uses the fire extinguisher on the bird, it falls to the floor - causing Howard to be upset at killing another bird. Howard gives the bird CPR, bringing it back to life. As they carry the bird out towards the door, a crow flies in. When Penny calls to check on the guys, she suggests they scrub their names from the sign-in sheet and just walk out.

At Amy's apartment the gang has just finished their Christmas dinner. Sheldon wants to exchange gifts and gives Amy the picture of him on Santa's lap. Sheldon is surprised to learn Amy has actually got him a gift. Amy called Sheldon's MeeMaw in Texas to get her cookie recipe and has made Sheldon a box of the cookies. When Sheldon tries a cookie, he calls them the perfect and wishes Amy a Merry Christmas.