Sheldon has just located his childhood hero, Arthur Jeffries Ph.D., online. He was better known as Professor Proton, host of a children's science show. Both Sheldon and Leonard were faithful viewers when they were children before the show was canceled. Professor Proton is still available for special appearances, so Sheldon decides to hire him for a small gathering at the apartment. When Jeffries arrives and finds only Sheldon, Leonard and Penny, he is confused as he expected a party full of children. But performing his Professor Proton show to the three allows him to open up about the dichotomy between the wants of Arthur Jeffries Ph.D., and the realities of Professor Proton. Meanwhile, Raj asks Howard and Bernadette to babysit his pampered dog Cinnamon for him. This babysitting experience demonstrates to Howard and Bernadette whether they are ready to graduate to having a real live baby.