Stewie was Nicky's best friend. After Nicky suddenly disappeared from the Underworld, Stewie became very upset and went in search of his best friend. He repeated Nicky's route and Stewie also made it to the surface of the earth. Stewie didn't know where to go, but when he came down from the volcano, he saw billboards all around with Nicky holding a can of soda in his hand. Stewie went to the mansion where Nicky lived, but the guards would not let him inside. He was very upset, and thought that Nicky had become a celebrity and forgotten about his best friend. Years later, Stewie has built a pretty good career as a doctor at the local hospital. One day Nicky was admitted to them in a very bad condition, the sheer amount of soda made Nicky diabetic. Soon stewie cures them, and they return home underground to develop underground medicine together.