Adult Sheldon explains that although he never liked surprises, his Meemaw thought they were a hoot. As Meemaw goes to open her front door to pick up the morning paper, Dr. Sturgis is waiting for her. After Meemaw asks what he’s doing there, John explains he’s there to surprise her. Mission accomplished, she says.
Inside, Meemaw asks Dr. Sturgis how things are going at the supercollider. John says up until 6:43 yesterday, things were going well. When Meemaw wonders what happened then, John admits that’s when he was fired. After Meemaw asks why, John says it was probably because of what happened at 6:14. A flashback shows John talking to a reporter who asks if local residents should be nervous about the supercollider being the next Chernobyl. John says absolutely not, as a supercollider can’t melt down like a nuclear plant. John says the worst it could do is create a giant black hole that could swallow up the Earth.
Meemaw asks John if he really thinks the supercollider could destroy the earth. John concedes it’s a one-in-a-trillion risk, so Meemaw suggests next time somebody asks if his work could destroy the universe he should just say no. John doesn’t think there’s going to be a next time, explaining that he’s been doing science all his life and thinks it’s time to try something new, like scrimshaw. Meemaw reminds John that he’s a scientist, but he points out he is 72 and has just lost his dream job. He thinks he needs to take a step back.
As Meemaw drives Sheldon to college, he is excited to hear Dr. Sturgis is back. When asks how John looks, Meemaw says the same. Sheldon was afraid he might have shrunk more. Meemaw insists not, but Sheldon points out they might have both shrunk. Sheldon is happy to think Dr. Sturgis will be back at the university, but Meemaw explains John is upset about getting fired and is looking for a change. Sheldon thinks an old person trying something new is funny.
When Sheldon meets with President Hagemeyer in her office, she wonders why she should hire John back. After all, he just caused a scare about the supercollider. Sheldon argues there’s no such thing as bad publicity, quoting P.T. Barnum. Hagemeyer points out that Sturgis left her in the lurch at the start of the semester, so why should she welcome him back? When Sheldon says it’s her opportunity to be the bigger person, Hagemeyer insists she would rather be the small, petty person. Sheldon asks again, saying please, and arguing it would make him happy if Sturgis returned. After all, Hagemeyer said his happiness was important to the university. When Hagemeyer asks Sheldon if he’s manipulating her, Sheldon admits it is fun to be the small, petty person.
Later, with Sheldon still in her office, President Hagemeyer calls Dr. Sturgis to offer him his job back. She is surprised when John says he has another job. Meanwhile, at Davidson’s grocery store, John goes to talk to Mary as she pays for her shopping. After Mary asks what he’s doing there, John explains he’s in between jobs so he took a job as a bag boy. Mary invites John to dinner this weekend, which he readily accepts.
That weekend, when Meemaw joins Mary in the kitchen, she thanks her daughter for inviting John to dinner. Meemaw admits she’s been a little worried about John since his previous episode, but Mary says John seemed stable when she talked to him. Meemaw points out John has a doctorate in science and is packing people’s groceries into bags. Mary argues John did a good job, though. As Meemaw says she’s sad to see John give up like this, Missy walks in and asks what they’re talking about. After Mary explains John’s situation, Missy jokes that at least he hasn’t given up being weird. When Mary tells her to behave, Missy argues she can behave at school or at home - but not both.
That evening, around the Coopers’ dinner table, John says it’s wonderful to see everyone and thanks them for having him. Sheldon says it’s great to see him, too. John tells Mary he recognizes the tater tots from when he packed them in her bags.
As Georgie asks Dr. Sturgis about his new job, he wonders if John thinks he looks 21. When John agrees, Georgie wants to know when he works. George steps in and says John won’t be selling him beer. Sheldon can’t understand why John doesn’t want to return to the university. John says he thinks it’s time this old horse was put out to pasture. John says science is a young man’s game.
As they eat dinner, an emergency siren goes off outside. George can’t understand a tornado warning this time of year. Georgie looks out and sees there’s not a cloud in the sky. As the family rush to the den and turn the TV on, a news reporter announces a black hole has formed in Waxahachie. As the family panics, they ask John what they can do. He says nothing, admitting they’ll never be able to outrun it. They have minutes at best. As the family start to face their final moments, Georgie wants to drink a beer, Meemaw wants to talk to her family one last time, George tells his kids he’s proud of them, Sheldon hugs his mother, Missy apologizes for being mean to Sheldon, Georgie apologizes for being awful to his father, while Mary leads a prayer for their safety.
Back to reality at the dinner table, Missy asks John if that’s really what would happen if there was a black hole. John confirms it’s one of the possibilities. Sheldon mentions that there’s also a theory that a black hole could open a wormhole to an alternate universe. As they sit around the dinner table, John is transformed into a cowboy, Georgie is balding, George Sr. is the religious one, Missy is the smart one, Mary is the party girl, Sheldon is the sports-obsessed kid, and Meemaw is the educated transplant from New York.
Back to their normal selves, Meemaw says John seems to be interested in this alternative universe thing, so maybe that’s something he could work on. After John jokes that maybe he is working on it in another universe, Meemaw suggests maybe he could do it in both. When John wonders what she’s getting at, Meemaw argues he could be doing something worthwhile rather than bagging groceries. John says there’s nothing wrong with him trying something new. After Meemaw points out has a PhD and is the smartest person in the room, John insists he’s happy doing what he’s doing. Meemaw doesn’t believe it, so John asks to see her outside.
On the porch, Meemaw apologizes to John for pushing him back into science, admitting that she worries about him. John is surprised to hear that, but Meemaw says he knows she cares about him. That means a lot, John says, admitting that if he could live in an alternate universe it would be one where they never broke up. After Meemaw agrees, they look into each other’s eyes as they lean in to kiss. John is snapped back to reality as Meemaw calls his name. Back in the dining room, Meemaw asks John what alternate universe he would live in if he could. John says he hasn’t really given it much thought.
As Sheldon and Dr. Sturgis continue their discussion about black holes, Sheldon says one interpretation is that if he were standing at the event horizon, he would be able to interact with his own twin. Missy points out she has interacted with him and it’s not great. After Sheldon claims that two of him would be unstoppable, he fantasizes about two Sheldon working together on a theorem before they start to get on each other’s nerves. Missy takes over the fantasy to have the two Sheldons fighting each other.
Later that night, as John walks Meemaw home, she asks if he’s doing okay. John says getting fired was tough but he’s glad to be back in town. Meemaw is happy he’s there and asks him to promise that he’ll seek help if he feels himself slipping again. John will. The conversation starts to pan out as John imagined earlier when Meemaw says she worries about him. John is surprised to hear that, saying it means a lot. As they reach Meemaw’s house, John passes on the chance to tell her he wishes they never broke up. Instead, he tells he’ll see her when she goes grocery shopping. As Meemaw turns to go inside, John stops her, only to say that Tuesdays are double coupon days.
Adult Sheldon says we often regret the things we don’t say. There’s a lot of things he wishes he told his dad while he was around. That he appreciated him. That he loved him. Which is why he’s grateful for the times he did tell him how he felt. As George watches TV and Sheldon reads a book in the den, Sheldon says tonight was fun. After George wonders why that is, Sheldon says Dr. Sturgis was here, everyone talked about science, it was nice. George agrees that it was.
As Georgie places a six pack down on the counter of the grocery store, the cashier, Madge, asks if he’s got ID. Georgie says dang it, he must have left it in his wife’s minivan. After Madge says she can’t sell him the beer, Georgie insists he’s 21 and tells her to ask Dr. Sturgis. After Georgie shouts over to Dr. Sturgis, a distracted John knocks over a pyramid of soda cans. Georgie says never mind.