In this week’s The Big Bang Theory, “The Mommy Observation,” Stuart collapses and the gang rushes over to help. Raj says that he has been “murdered,” revealing that he has set up a murder mystery and everyone is now a suspect.

Sheldon and Howard are still away in Texas where Howard was doing a talk for NASA. After the speech is done, they head to Sheldon’s moms house who lives in Texas to say hello.

Raj tells the gang that they are all playing themselves in the murder mystery, and they must speak with each other to figure out clues. None of the gang seems too excited to participate. Penny says she will look for clues in the beer, as she grabs one and starts drinking. The gang figures out that one of them “came from the future” to kill Stuart after finding a receipt dated 20 years from the current date.

Sheldon shows up with flowers and pie for his mom, but retreats back to the car after he looks into the window of the house. The two of them then wind up at a bar. Sheldon confesses to Howard that he saw his mom with a naked man “trying to become a mommy again.” Howard tries to make Sheldon feel better about the situation, and explains that it has been awhile for his mom. Sheldon disagrees saying that he should get a vote since he used to, as he put it, live in her genitals.

Raj gives the gang member details of their future like Amy bought the comic book store and closed it down so Sheldon would pay attention to her. According to Raj, Penny became a famous actress and Leonard, a professor at Stanford. Raj points out that the two of them drifted apart. This sparks Leonard and Penny to discuss what would happen if they both became successful. Leonard is worried they really would drift. Penny says if she becomes famous, Leonard would move with her and they wouldn’t need the money he would be making. Leonard says he wouldn’t want to leave the university especially if he gets tenure.

Sheldon shows up at his mother’s house and they talk about her relationship. She tells Sheldon that the man is someone she met at her prayer group. Sheldon gets snarky, saying that she reads the bible yet desecrated the sofa. His mom sends Sheldon to his room, even though he repeatedly tells her that he is a grown man.

Penny and Leonard continue to debate about their future. Stuart, who is supposed to be dead, says he believes that Penny and Leonard are the best couple because they make each other better. Penny thinks this is heartfelt and says she feels bad for murdering him, giving away the mystery.

Howard visits Sheldon who is in his childhood bedroom. Howard tells Sheldon how he felt when her mom started seeing someone and how it was hard for him. He says that he feels guilty because he got in the way of his mom’s relationship. After it ended she has been alone ever since. Howard says Sheldon shouldn’t get in the way of his mom’s happiness.

Sheldon goes downstairs to see his mom. His mom apologizes for what he saw. Sheldon says that he doesn’t like the hypocrisy that is goes against everything she believes and has taught him. Sheldon says it is confusing but he wants her to be happy so he will display an outward feeling of acceptance while he condemns her on the inside. Sheldon starts to give his mom the sex talk. His mom looks up and says “Oh, Lord” to which Sheldon responds “Don’t look to him, he is mad at you.”

Penny apologizes to Raj who is pouting because the game was ruined. Bernadette says she hopes in 20 years they are still friends. Leonard proposed that the group will meet in front of the same building in 20 years in the future and have dinner like they always do. The episode flashes forward 20 years and just an older Stuart is standing there alone.