Season 2, episode 9

Nobody dies in ''4 Days Out.'' There are no climactic shootouts, breathtaking action set-pieces, or awesomely quotable badass monologues. (Walt wouldn't even dub himself ''the one who knocks'' for two more seasons.) Where other classic episodes are big and flashy, it's quiet, contemplative, and utterly simple: just Walt, Jesse, and a marathon meth-making session gone horribly wrong. This is Breaking Bad at its most elemental — as well as its most gripping. (Appropriate for a show about chemistry.) And though the hour is a tightly constructed examination of Walt and Jesse's relationship — sort of like ''Fly,'' but without the artiness that grates on some viewers — that's not all it has to offer. Between Funyuns, Walt's withering appraisals of Jesse's judgment (''You brought a meth lab to the airport?''), and Jesse's incredulous guess at how Walt will get them out of this mess (''A robot?''), it doubles as Bad's funniest episode. ''4 Days'' also delivers one of the series' best endings: Walt learning that his cancer is in remission, then responding to the news by savagely beating a metal paper towel dispenser. It's a beautifully executed moment of ambiguous rage — as well as a vital turning point for Walt, Heisenberg, and the show at large. —Hillary Busis