I will admit to never having heard of Katia and Maurice Kraft before I watched this, and although I did find it interesting, I cannot really say I am too much the wiser about them now either. What makes this documentary work is the amazing footage of nature at it's most beautiful and hostile. It is very clear that these two were unafraid of taking considerable risks to gather images to not only illustrate the sheer explosive power of these natural phenomena, but also to use what they could accumulate and observe to try the almost impossible task of predicting what might happen when and where. The ultimate design for that information being the mitigation of some of the human risk for the populations adjacent, both near and far, as millions of tons of ash, rock, gas, smoke - you name it - emanate from the innards of the Earth. I found the narrative a bit dry. The couple come across as extremely dedicated, almost eccentric at times, but sadly we don't really get to know enough about them, what made them tick - what compelled them to this riskiest of careers. The commentary also lacks for gravitas, I thought. It needed someone just a little weightier than a competent, but rather mono-tonic Miranda July. All of that said, though - the footage is astonishing. The perilous undertakings of those filming it (and some of their makeshift heat resistant technology that looked like it was built from the stuff we wrap a Christmas turkey in) is well illustrated and thoroughly engaging to watch. Fascinating.