Warning: Spoilers ahead for the Season 3 finale of Young Sheldon. Read at your own risk!
Well, look at that. Just when I thought that Young Sheldon couldn't connect to The Big Bang Theory any more than it already has, especially considering that visit to Caltech and look at the most famous cafeteria in the history of TV a few months back, the comedy has managed to surprise in two ways tonight. First, it turns out that we hadn't heard the last from Caltech, and, second, a certain segment from The Big Bang Theory got a major preview tonight. Let's dive in, shall we?
Believe it or not, everything started because of a chunk of hot dog. Sheldon is in the kitchen and manages to release a small disk of cut hog dog from the confines of their counter. When the hot dog bit rolls across the floor and lands under the refrigerator, he asks Missy for help locating a flashlight. It turns out that there's one in Mary's bedside drawer, so Sheldon goes to fetch it. But, when he opens the drawer he not only finds that flashlight, but an envelope from Caltech addressed to "The Parents Of Sheldon Cooper."
He's curious, of course, but doesn't want to read it because it's not addressed to him and he fears he could be charged with the federal crime of mail tampering if he gets caught. Missy says that she's willing to read it and tell him what it says, so after a (probably not so quick) call to a local law firm to see what his options truly are, he tells Missy to give him the details. As you might imagine, Missy would like to extract some payment for said information, so she makes Sheldon dress up as a "princess rodeo clown" and let her take pictures first. With the bill paid, Missy tells Sheldon that Caltech is trying to recruit him, and they want him to study there. Big Bang Theory, here we come!
As soon as Mary gets home, Sheldon confronts her with the letter, asking why he wasn't told about it. Mary is upset that Sheldon was snooping, but tells him that he's not going so he didn't need to know about the letter. After Mary sends him to his room for looking through her things, though, Sheldon sneaks out the window and finds George at his favorite bar to ask him why they didn't tell him about the letter. And, when George asks to take a look at the letter, it's becomes pretty obvious what's going on.
Mary didn't tell George about the letter from Caltech at all, and when he gets home with Sheldon they have a big argument about it. George tells Mary that she can't just make major decisions like that on her own, especially since this could be a big opportunity for Sheldon. When he says that Sheldon's his son, too, and he needs to know about such things, Mary hits him with "well, he didn't feel much like your son when he had the flu," but George tells her that Sheldon felt like his son when he took him to Caltech a few months ago and he saw how excited he was to be there.
Later that night, before bed, Mary tells George that she should have told him about the letter from Caltech. Lest you think this solved the problem, though, she also admits to hiding letters from colleges in New Jersey and as far away as Germany. George. Is. NOT. HAPPY. So, the next day at school he gives Sheldon a football-style pep talk and helps him come up with a way to convince Mary to let him go to college. And, what do we see when they get home and try to talk to Mary? Well, just take a look, Big Bang Theory fans, and tell me what you see:
Still having trouble? Well, just insert a flag on each side of that chalk board and you have a very early version of Fun with Flags, the web series hosted by Sheldon and Amy from his and Leonard's apartment for many seasons of The Big Bang Theory (which star Iain Armitage was quick to remind fans of on Twitter). What George and Sheldon did was make a video at school, featuring all of Sheldon's teachers explaining why they felt he should be allowed to go to college. Sheldon also made sure to introduce the video by saying he didn't expect to be allowed to go away for school right now, but he wanted to be able to go to East Texas Tech and continue his studies with Dr. Sturgis as a full time student.
The end of the video featured Dr. Sturgis telling Mary that he knows this is a hard decision for her, but if she let Sheldon become a student there, they'd all take care of him. After the video plays, George has Sheldon leave the room so he can talk to Mary, and when he says, "Well?" she responds by saying, "I guess our baby is going to college." Several achievements unlocked!