As Sheldon opens up his safe to retrieve his membership cards, Adult Sheldon explains that from a young age he was a member of a number of elite organisations. Best of all, the Natural Science Museum of Texas, membership of which included a free subscription to their magazine. Outside, Sheldon picks up a “juicy” issue on the secrets of carbon dating from the mailbox.
In the kitchen, Mary and Meemaw are preparing dinner as George enjoys a drink. When Sheldon gets back inside, he asks if someone will drive him to a lecture on carbon dating this Saturday at the Natural Science Museum. George says he would be happy to, offending Meemaw whose yard sale he had promised to attend that day. George jokes that by learning about carbon dating, they could figure out how old Meemaw really is.
As George drives Sheldon out of Medford, Sheldon is reading the museum’s magazine. When he asks his father whether he believes that fossils are millions of years old, George answers that he does. After Sheldon points out that this contradicts Mary’s religious beliefs, George tells him the key to a good marriage is not discussing subjects on which they disagree.
Back home, Meemaw is setting up tables on her front lawn so Missy and Georgie can carry the items out from the garage. When Georgie comments that he can’t believe she thinks she’s going to get $10 for a piece of junk, Meemaw tells them she wanted to leave a little room to haggle. Missy and Georgie aren’t familiar with the concept of haggling, so Meemaw explains it to them. They get first hand experience when Meemaw haggles with them over their pay for the day. From their opening offer of $5 each for the day, Meemaw convinces them they actually her $2 dollars each. Meemaw goes soft on them as they’re family and agrees to call it even. Elsewhere, when they arrive at the Natural Science Museum, Sheldon and George are impressed by a dinosaur display.
When Mary shows up at Meemaw’s yard sale, she is surprised by how much of her late father’s stuff Meemaw is selling. Mary gets sentimental over her late father’s possessions, even his first attempt at taxidermy, Meemaw offers to sell Mary the stuffed raccoon for $5, but Mary realizes it’s not worth that. When Mary questions why Meemaw is selling her father’s golf clubs, shoes, clothes and pipes, Meemaw argues it’s just stuff and sends her daughter away so she can get on with selling it.
At the museum, George gets Sheldon seated in the front row of the carbon-dating lecture. George tells him not to wander off and says he’ll pick him up right after the lecture. Sheldon is not at all concerned about being left alone. After George finally leaves, an excited Paige walks over and sits next to Sheldon. She’s really happy to see him, even if he’s not immediately happy to see her. Sheldon decides to return to reading his magazine.
As George tucks into his food at a nearby dinner, he is excited to watch the football game on TV. Unfortunately for him, Paige’s mom, Linda, arrives and sits down in the booth with him. After she explains she just dropped Paige off at the lecture and asks George if she can join him, he somewhat reluctantly agrees. When George asks where her husband is, she makes it clear she really doesn’t care. After George asks if she would mind if he watches the game, Linda says no, but she then starts sobbing over the pie menu. George doesn’t know what to say when she admits she’s worried her and her husband are heading towards a divorce.
At the museum, Dr. Barrett is pleased by the turnout as she starts her lecture. She’s particularly impressed to see two young people in the front row. As she chats to Sheldon and Paige, Paige appears very smart as she compliments Dr. Barrett on her article. Sheldon struggles to think of what he can add, explaining that he found out about the lecture in the magazine. Dr. Barrett asks Paige to kick off the lecture by explaining what carbon dating is. After Paige concisely explains the topic, Dr. Barrett asks if there’s anything Sheldon would like to add. Sheldon is momentarily lost for words, until he thinks to mention that carbon dating is how they figured out how old his grandmother is. Sheldon is pleased to find he’s not only brilliant, he’s also hilarious.
Back at the diner, George is eating his chicken wings and trying to watch the game as a sobbing Linda says he would understand the difficulties she faces raising a special child. George explains that he and Mary have a system for dealing with it: they never talk about it. Linda doesn’t think that could work, but George points out he’s having a nice day while she’s crying into her peach cobbler.
At the museum, Paige tells Sheldon she’s getting bored by the basic nature of the lecture and wants to get out there. Sheldon says he can’t leave as he promised his dad he would stay there until the end. Paige tells Sheldon he can be a baby if he wants but she’s leaving, so she gets up and sneaks out of the lecture. Offended by the suggestion he’s a baby, Sheldon hastily follows after Paige.
At the yard sale, Billy Sparks tells Missy he likes the stuffed raccoon, but it costs $5 and he only has fifty cents. Missy says that’s okay as they’re haggling, but Billy doesn’t know what it means. She explains that he makes her an offer and then they meet in the middle. The middle of what? Missy’s not sure either. Meanwhile, Dr. Sturgess tries on a jacket he found in the yard sale. Meemaw gets emotional about him wearing her late husband’s clothes and tells him it’s not for sale. When John queries this as there’s a price tag on it, Meemaw curtly tells him to take it off. After John wonders whether this is a bartering technique, Meemaw snaps and shouts at him to take it off. As John is confused by what just happened, Mary explains it was her father’s old jacket but John still doesn’t understand.
As Sheldon and Paige walk through a corridor in the museum, she asks him if he thinks humans will one day become extinct like the dinosaurs. He does, but first he thinks some of them will merge with computers and become cyborgs. Paige is impressed with that idea, but wonders whether he got it from a TV show? Sheldon informs her it actually came from a comic book.
As George continues to work on his chicken wings and try watch the TV, Linda tells George about how she and Barry moved to the heart of Texas so Paige could be in a school for gifted children. Barry didn’t like the idea of giving up his dental practice in Lafayette and he’s been cool to her ever since, even though his practice here is making money hand over fist. When Linda suddenly gets anxious, she tells George he never saw her and then crawls away from the table. As George tries to process what just happened, Barry walks in the restaurant door and sees George. After he comes and sits in the booth with George, Barry explains he dropped Paige of at a lecture next door while George feigns ignorance.
At the museum, Sheldon and Paige reach a sealed off “Early Man” exhibit. When Paige decides to climb through the plastic sheeting into the exhibit, Sheldon points out it’s closed. Paige once again calls him a baby, so he follows right behind her. At the diner, when Barry asks him if he’s seen Linda around, George lies and says he hasn’t. George asks Barry if he’s interested in football as it’s a close game on, but he admits he’s more of a tennis man. When Barry asks if he can confide in George, he finally accepts there’s no hope of being able to eat his food and watch the game in peace.
As Sheldon and Paige sit in the Early Man exhibit surrounded by figures of cave people, Sheldon remarks that it’s oddly reminiscent of dinner with his family. Paige admits that her family never eats dinner together. When Paige asks Sheldon if she thinks stone age families always stayed together, he says they had to as there were no lawyers. Paige says she thinks her parents are heading towards a divorce as they fight all the time, mostly about her. Sheldon thinks he’s lucky as he’s the glue that holds his family together. Their heart-to-heart is interrupted when a security guard knocks on the exhibit window to ask what they’re doing in there.
Back at the yard sale, Billy and Missy make a deal on the stuffed raccoon: He’s going to pay 15 cents a week and she’ll say hello back to him at school. When John goes over to apologise to Meemaw, she says there’s no need to apologize but John insists. He admits he didn’t realize that with them being in a relationship, him wearing her dead husband’s clothing would be emotionally challenging for her. Meemaw accepts his apology, but John can see she’s still not okay. Meemaw admits she didn’t expect that getting rid of her husband’s stuff would hit her so hard. John says he must have been a wonderful man since he was married to such a wonderful woman. After Meemaw says he’s pretty wonderful himself, she lets him have a hula girl lamp as a gift.
At the museum, George and Barry thank the security guard as they emerge with Sheldon and Paige. When Barry asks Paige what she was thinking, she says she got bored. After Linda arrives, George introduces himself as if they hadn’t seen each other in a long time. As the two families go their separate ways, Sheldon asks his dad if he knew that Paige’s parents are getting a divorce.
Back home, George goes up to Marry as she’s preparing dinner and cuddles her. When she wonders what that’s in aid of, George doesn’t think there’s anything wrong with appreciating his wife. After George tells Mary that Sheldon and Paige skipped out of the lecture and snuck into a closed exhibit, Mary can’t believe George is proud of Sheldon. Mary says she doesn’t want to talk about it, prompting George to reply that’s why he loves her.
At dinner that evening, the cacophony of noise as the family eat prompts Sheldon to see them in another light: as cave people.