It is easy to see the beginnings of things, and harder to see the ends...especially if the ends involve M60 machine guns. After 61 episodes of exploding turtles, pink teddy bears, toilet epiphanies, and meth-making montages, Breaking Bad finishes tonight. Vince Gilligan says the finale will be "emotionally exhausting for fans,” while writer Thomas Schnauz notes that his wife "cried at a few of the plot turns near the end." A lot of people have exhaustive theories on what's going to happen, but I'd rather take a moment and look back at where this all started, and one of many things BB has done better than any other show.

AMC - Breaking Bad Pilot - Leaked Clip from mono on Vimeo.

This was the beginning of things: some quiet, still shots of the New Mexico desert, a pair of pants falling to the ground, an RV blazing a trail of dust, and then our first glimpse of Walter Hartwell White. From the cold open of the pilot, the show we were watching was already the show we would be watching for six years. Even though we don't understand why Walt is flashing a gun in his tighty whities and saying goodbye to his family, it is a thrilling way to start a show.

But plenty of shows can start strong—hell, Low Winter Sun had a similar in media res jump start, and look how that has turned out. It's the scene below, the second scene in the show, which lays out Gilligan's thesis:

Chemistry is the study of matter, but I prefer to see it as the study of change. Now, just think about this: Electrons, they change their energy levels. Molecules change their bonds. Elements, they combine and change into compounds. Well that's... That's all of life, right?

It's the constant, it's the cycle...It's solution, dissolution, just over and over and over. It's growth, then decay, then transformation. It is fascinating, really.

That speech gives shape to Walter White's metamorphosis from milquetoast suburban dad to ruthless meth king to banished dying man in a cabin. Again and again, I come back to this: Gilligan and the writers understood who this character was from the start, and they understood where they were taking him. I can't think of another show that had such a clear perspective on the story it intended to tell.

And at the same time, they left plenty of room for improvisation: so when the actor who played Tuco had to be written out, it provided an opportunity to create Gus. It's why the Cousins showed up at Walt's house in the second episode of the third season even though they were originally slated to be the main antagonists that year. The writers constantly painted themselves into corners—how would Walt and Jesse escape the RV with Hank right outside, how could Walt defeat Gus, why did Walt have a machine gun (and hair) in the flash-forward—and relished coming up with ways out.

This mix of foresight and balletic ad-libbing which made the show so remarkable; it's what made plot twists exhilarating and inevitable all at once. Gilligan and co. may not have known the details of how the show was going to end in 2008, but when we watch tonight's episode, we're watching a loop being closed that has been expertly guided all along.

Breaking Bad is not perfect by any means, but it has achieved what it set out to do from the beginning with a singularity of purpose. Unlike its peers, there were no theater troupes (Deadwood), no Johnny Cakes (The Sopranos), and no Glenn Close guest arcs (The Shield). We may not have delved into the pervasiveness of the drug trade, what was going on in the Czech Republic, or how Gus came to power, but we saw the story the writers set up from the start play out in excruciating, exacting detail. And after 10:15 p.m. tonight, we'll be left with a complete 62 episode story that saw one man go through growth, decay and transformation again and again.

Until he dies. Walt is definitely going to die.