Breaking Bad extremely playful on set, with Aaron Paul describing him as "a kid trapped in a man's body". Gilligan originally intended for Aaron Paul's character, Jesse Pinkman, to be killed at the end of "Breaking Bad"s first season in a botched drug deal as a plot device to plague Walter White with guilt. However, Gilligan said by the second episode of the season, he was so impressed with Paul's performance that "it became pretty clear early on that would be a huge, colossal mistake, to kill off Jesse". Donna Nelson, a professor of organic chemistry at the University of Oklahoma, checked
Fly (Breaking Bad) television we're likely to see this year." In "TIME", James Poniewozik called it "the most unusual and very possibly best episode of Breaking Bad so far", comparing it favorably to "The Sopranos"<nowiki>'</nowiki> "Pine Barrens". In "Entertainment Weekly", Ken Tucker said he would be "shocked if both Bryan Cranston and Aaron Paul don’t use the episode for Emmy consideration", and lauded it for "[opening] up to become an opportunity for Walt and Jesse to explain more fully the sadnesses and regrets they have over everything". Alan Sepinwall, writing for "HitFix", speculated that "Fly" may be "the best bottle show ever" and