Following the murder of Gale Boetticher, Walt and Gus enter a cold war. Gus seeks to replace Walt with a more compliant Jesse, while Walt becomes increasingly paranoid and desperate to eliminate Gus.

Despite his physical recovery, Hank becomes obsessed with Gale's lab notes, eventually connecting the evidence back to Los Pollos Hermanos and putting Gus directly in his sights. Key Episode Guide

Skyler takes a lead role in the criminal enterprise by orchestrating the purchase of the A1A Car Wash to launder Walt's drug money under the guise of a gambling addiction story.

The season is defined by several legendary episodes that culminate in one of the most famous finales in TV history: Breaking Bad 4x11 Crawl Space: A Critical Guide