In "Fire of Love,” the voice-over quotes Maurice and Katia Krafft’s feelings about the risks in their line of work: exploring and filming volcanoes. "I prefer an intense and short life to a monotonous, long one,” Maurice wrote. Katia acknowledged the danger but said that in the moment, she didn’t care at all.

The Kraffts, married French volcanologists, were killed June 3, 1991, observing an eruption of Mount Unzen in Japan. But the stunning 16-millimeter footage they shot throughout their careers — full of gushing lava, flying rocks and giant clouds of smoke — lives on in the new "Fire of Love,” an all-archival documentary compiled from roughly 200 hours of their material along with 50 hours of TV appearances and other clips.

"I have so many questions that I wish I could have asked them personally, and one of them is what reels didn’t make it,” Sara Dosa, the documentary’s director, says during an interview in Tribeca last month. After all, visiting volcanoes is fraught with hazards. The film tells of Maurice scalding his leg in boiling mud and shows him playfully testing Katia’s helmet by throwing a rock at her head. Dosa says they didn’t use "a fun shot we had of Maurice taking his melted boot and throwing it into a lava flow.” It’s safe to assume that not all of the couple’s film equipment survived, either.