It is Season 3, Episode 6 of AMC's Breaking Bad, halfway through the season in which high-school-chemistry-teacher-turned-meth-maker Walter White (pictured here) gets installed in a state-of-the-art meth lab to cook for drug kingpin Gus, mild-mannered owner of the fast food restaurant chain Pollos Hermanos. Walt's cancer is in remission, but he's trying to salvage his marriage (Skyler wants a divorce and is sleeping with her boss) and his relationship with his son. Walt's brother-in-law Hank is obsessed with finding the source of the blue meth that Walt has made famous, and he's tailing Walt's former partner Jesse Pinkman in hopes of tracking down the RV he (correctly) suspects of being a mobile lab. Pinkman is clean and just out of rehab but is talking with his friends about getting back into the biz as dealers.
That's when Walt meets Gale (pictured here), the lab assistant that Gus has provided. Gale, it turns out, is everything that Pinkman was not—unassuming, respectful, collaborative, trained, and, most of all, as passionate about the chemistry as Walt. Explaining how he ended up in the meth cooking business, Gale thinks back to graduate school and explains, "I was on my way—jumping through hoops, kissing the proper behinds, attending to all the non-chemistry that one finds oneself occupied with. You know that world. That is not what I signed on for. I love the lab—because it's all still magic, you know? Chemistry? I mean, once you lose that...."
Walt agrees. "It is. It is magic," he says. "It still is."
And then, because Breaking Bad can't exactly break into song to express the magical chemistry moment that Walt and Gale are experiencing, Gale breaks into a poem. "And all the while," he tells Walt, "I kept thinking about that great old Whitman poem, 'When I Heard the Learn'd Astronomer.'"
Walt: I don't know it.
Gale: Well, anyway ....
Walt: Well, can you recite it?
Gale [laughing]: Pathetically enough, I could.
Walt: All right, well, come on, come on.
Click the video here to watch Gale's recitation: