3. The Season Four Finale (Season Four, Episode Thirteen)
Initially Guss death and the revelation that Walt had indeed poisoned Brock were going to be separate entries, but for the sake of not having multiple moments from the same episodes they've been combined. This was also one hell of a season finale, so lets dive right into it. Gus needed to go. If he didn't then things weren't going to end well for Walter, or the rest of the White family given Guss solemn promise to kill not just Walt, but all of his family including his infant daughter in one of the most chilling of Giancarlo Espositos line deliveries. After a failed attempt to kill Gus using a car bomb, Walt figures out that they have a mutual enemy. One who, as Gus mentioned in a previous episode, has nothing left to live for Hector Salamanca. So, Walt takes the car bomb, wires it to Hectors wheel chair, and finally gets rid Gus once and for all. This plan never would have worked without the aid of Jesse. As Walts worth to Guss operation perilously decreased, it looked less likely that he would survive. Knowing that Jesses loyalty to him had vanished, Walt needed to devise a plan, and what he came up with was the most vile thing that he had done up until this point. Brock ends up in the hospital, having been poisoned, which leads Jesse naturally to assume that due to his insistence on using ricin, it was Walt. Things play out so frantically that viewers were left unsure of whether or not Walt actually did the deed, or if his pleas to Jesse that it was the work of Gus to manipulate him into killing Walt were the truth. Then the tests came back, and it turns out that Brock was poisoned because of his ingestion of a Lily of the Valley. Giving confirmation to both Jesse and viewers that Walt was in the clear, and that he hadn't reached that low of a point. That is, until the final shot of the episode. In the Whites backyard by the pool the camera zooms out, and shows a flower pot labeled, Lily of the Valley revealing that yes, Heisenberg has taken over as the full time persona, and Walter White has become as evil as we all thought.