Walter's working away, not in his lab, but in his kitchen, to the sounds of that "Mah-Nà Mah-Nà" song, which has to be one of the most spectacularly annoying songs to ever enter into our collective pop-culture subconscious. It was even annoying when the Muppets sang it, for God's sake! Great. Now I'm in a bad mood.
Anyway, there are liquids bubbling away in beakers, and Walter draws an opaque green liquid into a syringe and then starts unbuckling his belt, which is when a bleary-eyed Peter strolls into the kitchen, and Walter says, "You're up early," and Peter, in a surprise twist, says something rude and sarcastic to his dad. In Peter's defence, he did wake up and come downstairs to find out that Walter, despite having a lab at Harvard and a hundred more at Massive Dynamic, has taken over the kitchen with Bunsen burners and tubing, and is currently bent over in the living room about to inject something into his arse, which is clad in boxer shorts with multicoloured guitars all over them. This is probably how Timothy Leary's kids grew up. Walter assumes that Peter is just checking to see if Walter's high, although the "Is Walter High?" test really consists of the following question: "Is Walter awake? If yes, then Walter is high."
Walter says he's making himself smarter, because maybe he feels that his life's work to date hasn't killed or maimed or infected enough people, and he reminds Peter that William Bell removed parts of his brain years ago. "And now, I'm not the equal of myself," he says, by which he means Walternate: "If I can think like him, I can figure out what he's trying to do with that device and how to keep you safe." I think maybe Walter should just try wearing a suit once in a while. Dress for the job you want, not the job you have!
Peter stops Walter from injecting himself by reminding him that William Bell took out those pieces of Walter's brain on Walter's own instructions: "Because you were afraid of what you were becoming. I don't wanna see you hurt yourself."
Walter briefly looks touched, and then says he won't hurt himself, and jabs himself in the thigh. Then there's a knock at the door: the pizza Walter ordered. He shuffles off to answer the door, pants around his ankles. "So you are high, then," says Peter, and Walter admits he is, maybe a bit. What a treat for the pizza delivery man -- Walter high, with a needle sticking out of his thigh, pants around his ankles. Probably not the Penthouse Letters scenario that pizza-delivery men concoct for themselves to make it through another shift.