Bryan Cranston on his new book, A Life in Parts

Bryan Cranston. Amy Sussman / Invision / AP

Bryan Cranston seems so far apart from the murderous Walter White that one wonders how he was able to channel such darkness with Emmy-worthy ferocity in Breaking Bad.

But in his new memoir, A Life in Parts, Cranston ­details a ­real-life incident that helped him get in character: an ­unhinged ex-girlfriend who threatened his life and triggered violent thoughts within him.

It's one of the more revelatory moments in the book, ­released earlier this month. The 60-year-old acclaimed ­actor covers everything from his early childhood and his ­signature role on Breaking Bad to personal challenges.

You write about wanting to kill your ex-girlfriend. What drove you to that?

I was flush with fear and I felt like a trapped animal - I realised that I was capable of killing someone. That experience helped me in developing Walter White in the transition that he made, because Walter had to come to terms with that himself.

What made you want to write a book at this point of your career?

I am aware from an objective point that the wave, the tsunami wave that Breaking Bad created, also created tremendous opportunity for me, and there is a peak and valley to careers and that includes fame. If you are lucky to ride this wave of fame to a plateau – it won't last there. I guess it is just a blue-collar work ethic that I was raised with.

In the book, you talk about your dad being dissatisfied as an actor. Why follow in his footsteps?

It was in my DNA, and they were actors – my parents were both actors – that was part of it. So really when you think about it in that sense, you’re going into the family business, so it’s very common. The turmoil that my dad went through, and then by extension, the kids went through, was profound and disastrous for the marriage, for the ­family.

How long do you plan on working?

When the sun is shining, make hay, because it would be sunset on my career at some point, and when it is, I want to be ­exhausted. I want to be done, and actually go: “I had a good run. No regrets. I’m ready to step aside.”

* Associated Press