Walt finds an unexpected ally in an attempt to kill Gus Fring.

Walt takes drastic action to protect his secret and Gus.

Gus reconnects with some old friends, leading to a deadly confrontation.

Jesse gets alarming news and rushes to meet with Walt.

Hank enlists Walt to investigate a theory.

Walt and Jesse face the deadly consequences of their actions.

Skyler's past mistakes come back to haunt her.

A frustrated Walt gambles on a risky new plan.

Skyler has an unlikely reunion.

Jesse’s activities draw unwanted attention.

Skyler makes an unsettling discovery.

Walt attempts to form a new alliance as he plans his next move.

Events spiral out of control at Jesse’s house.