Breaking Bad star Bryan Cranston can tap into his character's dark history in the hit drama, because he knows how easy it is for happy, normal people to snap and do very bad things.
The actor plays a science teacher who becomes a kid-poisoning methamphetamine dealer and killer on the show, and he admits he didn't have to dig too deep to find Walter White.
He tells Men's Journal magazine he once had a girlfriend he briefly considered murdering after the drug-addled mess refused to accept their relationship was over.
Cranston says, "I had an out of body experience and at that moment, I realised that, given the right circumstances, I was capable of doing very bad things. Everyone is. It was the most amazing, uncomfortable experience of my life."