Leonard, Sheldon and Amy run into Leonard and Sheldon's childhood hero Arthur Jeffries, aka Professor Proton, the scientist host of their favorite childhood television program. Because of this re-acquaintance, Arthur, who always wanted to be a true scientist as opposed to a kid's show host, asks Leonard to read and review a paper he is writing, but he doesn't ask Sheldon, which Sheldon can't understand. With some innuendo from Amy, Sheldon finally realizes that it's because he annoys Arthur. Sheldon tries unsuccessfully to make amends with Arthur so that he can collaborate on the paper. Without the friendship of his childhood hero, Sheldon decides to get a replacement model. Arthur makes Leonard truly examine his friendship with Sheldon, and in turn Leonard ends up getting Arthur to see Sheldon in a slightly different light. Meanwhile, Raj has been invited to girls' night with Penny, Amy and Bernadette. Raj's night with the girls ends up being taken over by an unexpected fifth.