Breaking Bad Season 4 Episode 12 (10/02/11)
With his son and wife secure at Hank's place, and DEA agent keeping watch, Walt locks himself inside this week and prepares for Gus' men to arrive.
They do not, but Jesse shows up in an angry panic because Brock has been poisoned by ricin. He assumes Walt did and confronts his former mentor. But Walt convinces him that Gus somehow did it in order to get Jesse's permission to kill Walt. Jesse sees the truth in this and the pair decide to go after Gus.
Walt makes a homemade bomb and is prepared to detonate it in Gus' car as he and his henchman walk toward it. But they turn around at the last moment as the episode ends.
Elsewhere, Gomez takes Hank's advice and searches the laundry center. But he doesn't find any evidence of a lab there.