By the start of Season 4, the story shifts from a struggle for survival into a psychological and tactical war between Walter White and the powerful, calculating drug lord .
: Walt has successfully navigated the local drug trade, but now finds himself under the thumb of Gus, who runs a sophisticated multi-state distribution network hidden behind a legitimate fast-food chain, Los Pollos Hermanos.
: Every action has a reaction. Small details from earlier seasons often return with massive consequences, making for a highly cohesive and rewarding viewing experience.