Bryan Cranston definitely has the ability to scare a guy silly as TV's most ruthless drug manufacturer Heisenberg Walter White in "Breaking Bad" (all the while appearing as a jarringly pleasant day-saver in films like "Argo" and a well-meaning shopkeep in "Drive").

In real life, though, if you saw him on the street you'd probably stop to hug ... or at least get a Twitter picture, no? 'Cause when he's not running drug circles and such, he's probably a nice enough guy, right?!

Well ... In the August issue of GQ, the "Godzilla" star revealed that he once had a pretty bad moment of monstrosity: that time he thought about violently murdering his girlfriend. Yeah, this is going to get kind of intense, so strap in. 

According to GQ, the situation was set up as such: After his first marriage, he dated a girl who was an obsessive drug addict, and she followed him from L.A. to New York when he landed a soap gig. Evidently, the chick went a little nuts and left him messages like "I'm going to kill you." and "I'm gonna have your d*** sawed off." So, yeah, not exactly your girl next door, then. Even so. One day, the woman showed up at Cranston's Upper West Side apartment banging away at the door, and he lost it. The dark thoughts took over.

"I envisioned myself killing her. It was so clear. My apartment had a brick wall on one side, and I envisioned opening the door, grabbing her by the hair, dragging her inside, and shoving her head into that brick wall until brain matter was dripping down the sides of it," Cranston graphically recalled.

Fortunately, though, he got it under control soon enough. "I shuddered and realized how clearly I saw that happening. And I called the police because I was so afraid," he said. "I was temporarily insane — capable of doing tremendous damage to her and to myself."

Calling the police on himself? That takes some guts, so is his mental murderousness forgiven, then? Hard to say, but one thing's for sure. Now we totally get where all that on-screen darkness comes from week after week ... he's got it all bottled up right there inside of himself.

On that note, maybe everyone should just give him wide berth on the street after all.