“For want of a nail the shoe was lost. For want of a shoe the horse was lost. For want of a horse the rider was lost. For want of a rider the message was lost. For want of a message the battle was lost. For want of a battle the kingdom was lost. And all for the want of a horseshoe nail.”

You could have an extremely entertaining argument over exactly when in Breaking Bad Walter White stopped being a decent man in a bad situation making extraordinarily bad decisions and became an evil person.  For me, the point of no return for Walt occurs both in the second season’s finale, but also brilliantly teased out over the course of the entire second season.  Through the whole season you kept getting expanding clues that we were headed toward a calamity….then it became more clear that calamity was a plane crash…but it wasn’t until the finale that it became clear that Walt’s decision not to save his partner’s girlfriend (Krysten Ritter) from her drug overdose was not only a clear case of murder by inaction, but would cause a chain of events that would cost hundreds of people their lives.

Walt’s decision to allow Jane’s death to occur, which he saw as a way to gain back the loyalty of his partner, between whom Jane was driving a wedge, ended having horrific consequences.  Turns out that Jane’s father was a airport traffic controller, and his showing up at work after the death of his child caused him to be inattentive, which then allowed two jets to collide over Walt’s neighborhood, dropping all the clues into place that we had been seeing laid out all season long.

Jane’s death/murder also was a pivot point in the journeys of Walt and Jesse’s characters.  While Walt became more amoral, more greedy, and more hardened, Jesse became unhinged, blamed himself, began trying to find a path out, and became more and more resentful of what was originally his lifestyle.  Walt kept the secret from Jesse until one of the show’s final episodes when he devastatingly reveals exactly what caused Jane’s death and you can see how far one decision caused someone to break undeniably bad.