In this week’s Big Bang Theory, “The Proton Displacement,” Professor Proton (Bob Newhart) is back. The Professor, also known as Arthur Jeffries, was a kids’ science show host that appeared on a previous episode when Sheldon hired him to do a private demonstration for him. This week, the gang ran into him in a pharmacy. Sheldon doesn’t want to bother him, so instead, he talks to him. This of course comes off as annoying and bothersome.

After the run-in, Arthur reaches out to Leonard, asking him to read his paper on nano tubes. Sheldon becomes upset that he was not asked to read it as well. Amy hints to Sheldon that he may come off as annoying.

Meanwhile, the girls are having a girl’s night and Raj is attending. They are going to be making jewelry, which Raj suggested. This prompts Howard to poke at him. Howard ends up joining them, showing them better ways to make jewelry using his soldering gun. Raj becomes annoyed by this.

Sheldon shows up at Arthur's house and apologizes to him. He then expresses his interest in reading his paper. Arthur however, only wants Leonard to read it. Sheldon asks if he is annoying and after some banter of trying to get Arthur to admit it, Arthur agrees that he is indeed annoying.

While Arthur and Leonard are working in the lab, Sheldon shows up with a friend of his own, Bill Nye the Science Guy. Arthur dislikes Bill, feeling like he copied his show.

At the next jewelry night, Howard shows up again with more tips for the girl’s jewelry making. Raj yells and explains to Howard that he dislikes him being there. He likes being with just the girls because he is able to open up to them without them making fun of him like Howard does.

At the lab, Arthur asks Leonard why he puts up with Sheldon. Leonard has a hard time with an explanation, but tells him that in some ways, they need each other. He also tells him that Sheldon doesn’t mean to be annoying on purpose and he is very loyal. Leonard then gets a message from Sheldon to come pick him up because Bill Nye ditched him in at a smoothie place.

Arthur shows up at the apartment and asks Sheldon to read his paper. Sheldon tells him that he already did because he hacked into his email. He tells him that it was inspiring. He ends up saying for tea, but only when sees that Penny is there. Sheldon also mentions that Bill Nye has a restraining order against him.

Raj, who wants to make things up to Howard for yelling at him, makes them both light saber belt buckles. What Raj doesn’t realize is that when they wear them, they look very inappropriate.