Back at America's Meth Kitchen, both Walt and Jesse are somewhat zombiefied, reeling from their recent revelations. Only Jesse forgets to put on his respirator, causing Walt to yell at him. Before they start cooking, there's a call on their little Batphone. They exchange quizzical looks and, with a deep sense of foreboding, Walt answers. It's Gus, and just like he always does, he turns something threatening (a mysterious phone call) into something domestic and innocuous (an invitation to dinner). Of course, Gus does the opposite -- turning the domestic and innocuous into something threatening -- just as well, so Walt can't be comfortable while dining with his boss.
The horrifically placid suburban home of Gus Frings scares me more than any of those dusty Mexican hovels where Tortugas got beheaded or statues of Santa Muerte got crawled to. It's aggressively beige, the kind of beige that actually allows Gus's tan sweater to pop. He invites Walt in the kitchen to help him cook, doing that thing he does where everything he says sounds like "I'm about to cut your heart out and serve it in my spicy chicken tacos." Example: he pulls out a giant kitchen knife, holds it in front of Walt for an uncomfortable few seconds, before turning the handle around and offering it to Walt so he can "slice the garlic."
Walt is appropriately suspicious as to why Gus asked him out here, but I'm surprised he asks him as much out loud. Gus delivers some platitude about working together and breaking bread together. As with most things surrounding Gus, you have to just let him get rolling for a while before you arrive at any truth. So Walt sits at his dinner table and listens to him yammer on about flavors and senses and how both take him back to his childhood. Ever the teacher, Walt mansplains about how it is that scents are tied to memories. It's through the hippocampus. I kid Walt about the mansplaining, but it's actually one of his more endearing qualities. Even if you can see that Gus receives it with a mixture of admiration for Walt's brain and a kind of Tony Soprano-esque resentment of anyone who might threaten his dominance in any area. So Gus decides to re-assert his dominance by offering to help Walt with this piece of advice: "Never make the same mistake twice."