With four and a half seasons of what is widely regarded as TV perfection behind him, Vince Gilligan faced one hell of a trial going into the final chapter of “Breaking Bad.”

“The greatest challenge of these final eight episodes was not to eff it up,” says the showrunner. “That really was it. I’m being funny, and yet I’m not.”

Gilligan and his writers knew well ahead of time that they had 16 episodes to finish the series, but clearing a path through the forest they had created was easier said than done.

“There’s endless options,” he says. “You tell yourself palatable lies sometimes to get through the day, and the lie we were telling ourselves at the end of season 5A was that it’s all going to be downhill from here — not in the sense of quality, but downhill in the sense of hard work. Instead, we realized there wasn’t one way through this story. There was about a 100 million ways.”

For Gilligan, who famously had pitched “Breaking Bad” as one man’s transformation from Mr. Chips into Scarface, there ultimately wasn’t a final destination he felt he needed to reach.

“I had different endings in mind as the years went by, but I’d forgotten half of them,” he admits. “The best way, it seems to me, to create a TV show is to allow it to live and breathe on its own. And the best way to write a character like Walter White is to let him tell you what it is he wants, what the goal is, what his fear is. Basically, my favorite kind of writing — and it doesn’t happen every day — almost feels like you’re transcribing a voice in your head.”

Those days were not as frequent as Gilligan and his six writers would have liked in the fifth and final season, but the environment they had created allowed for even the worst ideas to be considered.

“Bad ideas were embraced,” he says. “Not as a basis for creating the show, but as a means of leading to the good ideas. I wanted all the writers, myself included, to be free and comfortable throwing out the dumbest idea that they could possibly think of, because those always have a way of leading to the good stuff. And if we pleased ourselves, then, that was a good day.”

As the end of Walter White’s journey nears, Gilligan is at peace with their farewell.

“I’m not as nervous as I thought I would be,” he says. “I was very nervous before we broke the episodes, because I was afraid they wouldn’t be up to our standards. I know it’s impossible to please everybody, but I feel mainly excitement and pride about these final eight, and I’m looking forward to seeing what people think.”