The Bitcoin Entanglement Season 11, Episode 9 -  Aired November 30, 2017

The Bitcoin Entanglement

When Sheldon remembers mining Bitcoin a few years ago which are highly valued today, the guys go on a quest to track down their missing digital fortune. In the process, they turn to Penny's ex-boyfriend Zack and find a seven-year-old video which moves Leonard.

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Guest Stars: Kevin Sussman as Stuart, Brian Thomas Smith as Zack

Writers: Steve Holland (Story), Andy Gordon (Story), Jeremy Howe (Story), Dave Goetsch (Teleplay), Maria Ferrari (Teleplay), Anthony Del Broccolo (Teleplay)

Director: Mark Cendrowski

Viewers: 13.84 million Adults 18-49 Rating: 2.5/10

Available on iTunes

Episode Notes

  • The title refers to the guys' difficult attempts to retrieve their Bitcoin fortune.

> Sheldon's Knock

In a flashback to seven years ago, Penny tries to film a video message for Leonard explaining why she broke up with him and is interrupted by Sheldon knocking on her apartment door.

Episode Quotes

Sheldon: Oh, Stuart, good. I was wondering, will you be accepting Bitcoin?
Stuart: Well, I don't know what that is, but it's got "coin" in it, and my cash register doesn't, so yeah.

Mrs. Wolowitz: Howard, what's going on?! Are you boys roughhousing?!
Howard: No, we're not roughhousing! We're scientists! Scientists don't roughhouse!
Mrs. Wolowitz: Excuse me, Mr. Grown-up!

Mrs. Wolowitz: Howard, I made cookies for you and your little friends!
Howard: They're not my little friends, and we don't want cookies!
Leonard: Actually, a cookie sounds good.
Howard: All right, we'll have cookies! Thank you very much!

Penny: Leonard thinks when we broke up, it didn't bother me.
Zack: That's crazy. When we were going out, she used to talk about you all the time. In fact, I think she only dated me because I reminded her of you.
Leonard: Sure. Because we're both people?
Zack: Damn right we are.

Stuart: Huh. What's that? Ooh, Batman flash drive. Pretty cool. Huh, if I erase this, I could probably resell it for, like, ten bucks. Things are finally going my way.

News Stories

Title Date Posted
1109 'The Bitcoin Entanglement' Press Release November 17, 2017

CBS has released the synopsis for the next episode of The Big Bang Theory, "The Bitcoin Entanglement", which airs Thursday, November 30. Brian Thomas Smith reprises his role as Zack, Penny's ex-boyfriend, in the episode.  Full story


As the guys arrive at the comic book store, Raj shares his disappointment at the news that there will be four new Avatar movies, although his friends remind him how much he loved that movie. After Sheldon mentions an interesting article he recently shared on the recent spike in the price of Bitcoin, Leonard remembers they mined some of the cryptocurrency a few years ago. As the guys try to remember how many Bitcoins they mined, Stuart tries to muscle in, claiming to have been with them when they got the digital currency. After the guys ask Sheldon, with his eidetic memory, how much Bitcoin they own, they flashback to seven years ago:

In 2010, as they guys enter the comic book store, Raj can’t believe Leonard hasn’t seen Avatar yet. Leonard says says he’s only just started dating Penny, so he avoids crowds who might steal her. Howard arrives at the store, still on the phone talking to his mother. When Sheldon sees Stuart, he asks if he’s planning on accepting Bitcoin at the store. After Sheldon explains the concept behind the new cryptocurrency, the guys are excited at the opportunity to write code and “mine” Bitcoin. When the guys invite Stuart to bring snacks and join them, he says that’s too rich for him, so Leonard says it’ll just be the four of them. After Sheldon lectures them on the possible tax implications of acquiring lots of Bitcoin, the guys cut him out. Back in the present day, Leonard remembers that they did the mining without Sheldon. Sheldon said at the time that they would regret it and he tells them today’s the day, except Leonard instead thinks today is they day they realized they’re rich and don’t owe Sheldon anything.

Leonard and Raj wait for Howard as he searches the closet in Halley’s bedroom for the laptop he was using seven years ago. When Howard comes out with the laptop, Leonard asks Raj and Howard what they’ll do with their money. After Howard boots the laptop up, Raj notices a lot of “science” on the laptop, but Howard can not find the Bitcoin. Seven years ago, Leonard and Raj are with Howard in his room as he sets up his laptop to mine Bitcoin. As the mining code is almost ready to run, Mrs. Wolowitz interrupts them to ask if they’re “roughhousing”. When Howards’s laptop crashes, Leonard says they can use his laptop instead. After Mrs. Wolowitz calls again to say she’s made cookies, the guys leave Howard’s room.

Back in 2017, Sheldon and Amy are chatting about their wedding planning with Penny in the kitchen of the apartment. Sheldon and Amy admit they’re struggling to settle on a location as Sheldon has rejected all the cliffs Amy’s found. After Leonard, Howard and Raj come rushing in looking for the old laptop, Leonard can’t find it in the storage closet. After Sheldon suggests they need someone with an eidetic memory to remember where it is, Howard demands Sheldon just tell them, but Sheldon reminds them that they didn’t want him to be a part of this. Leonard can’t believe Sheldon is still carrying that grudge and begs him to reveal where the laptop is now.

In a flashback to the Cheesecake Factory in 2010, Penny goes to talk to Bernadette who’s serving behind the bar. Penny wants Bernadette to wait on an annoying table where Amy, not yet familiar with Penny, is sitting awkwardly with a man. After Amy asks Penny to take their picture, she then sends her date away and explains to Penny that she needs to prove to her mother she was actually on a date. After Penny goes to check on the guys’ table, Leonard asks Penny how her day’s going. Penny mentions missing an audition because her computer broke, so Leonard offers to give her his laptop. In the present, Penny remembers how sweet it was of Leonard to give her a laptop. When the guys ask if she knows where it is now, Penny explains that she gave it to her ex-boyfriend, Zack.

Still in the apartment, Penny gets off the phone with Zack and says they will be right over to collect the laptop. When Leonard says he can’t believe Penny gave away a gift from him to another man, Penny tells him not to make a big deal about it as they were broken up at the time. Leonard mentions that he and Penny weren’t the only ones to break up, as Howard & Bernadette also did. At the Cheesecake Factory seven years ago, Penny talks to Bernadette about her recent break-up with Howard, telling her the best thing would be to take some time and be by herself. After Penny is picked up by her new boyfriend Zack, she tells Bernadette to do as she says not as she does.

In the present, as Leonard and Penny leave the apartment on their way to Zack’s, Penny can’t believe Leonard is mad about her giving the laptop away years ago. Leonard admits he’s mad because he feels like he was more upset by their break up than Penny was. Penny says she was upset by their break-up too, but Leonard is jealous that she got together with Zack so quickly.

When Leonard and Penny arrive at Zack’s place, he says it’s good to see them and they should do it more often. After Zack realizes Leonard & Penny are fighting, she explains to Zack that Leonard thinks she wasn’t bothered when they broke up. Zack says that’s crazy, admitting that Penny used to talk about Leonard all the time when they were together. Zack then mentions a video on the laptop about how much Penny missed Leonard.

In 2010, a drunk Penny films a video for Leonard on her laptop, saying she was going to write Leonard an email but spelling is a sober person’s game. When Sheldon interrupts her filming, Penny tells him she’s making a video to explain to Leonard why she broke up with him. As the video keeps rolling, Penny tells Sheldon she went out with Leonard because he’s great, but that if they had kept going out she would probably have married him and that was scary to her. Back in the present day, Leonard is amazed at how much Penny loves him after watching the video.

When Leonard and Penny return to the apartment with the laptop, Howard searches for the Bitcoin but finds the folder is empty. Howard wonders if Zack stole it, but Penny insists he wouldn’t know how to steal Bitcoin as he waves at trucks. When Sheldon loudly wonders who might have moved the cryptocurrency, Amy makes Sheldon explain what he did. Sheldon admits sneaking onto the laptop to move the currency to a flash drive, claiming he waited seven long years for his moment of revenge to come. After Sheldon tells Leonard the best part is he moved the currency to the Batman flashdrive Leonard keeps on his key chain, meaning it’s been in his pocket this whole time, Leonard reveals he lost that keychain years ago.

Four years ago, as Stuart sweeps the floor of the comic book store, he finds a Batman flash drive and realizes he could erase it and probably sell it for ten bucks.