It’s rare for a documentary to be made long after its subjects have died but still feel like they tell their own stories, but “Fire of Love” manages to keep the passionate story between volcanologists Katia and Maurice Krafft alive and as fiery as it was while they lived.

And boy, did they live.

Director Sara Dosa crafts an incredibly special documentary about the Kraffts’ love not only for each other, but also what makes the planet bulge, belch and eventually blow. These passions are so intertwined, it’s hard to imagine one existing without the other.

Dosa and her team weave together archival footage of interviews with the Kraffts and hundreds of hours of footage the volcanologists shot during their research on the sides of gurgling volcanoes — meaning everything the audience sees is also what the Kraffts saw in the world around them.

Miranda July guides the audience through the Kraffts’ lives and work, pitch-perfect narration that borders on poetry. Her slow, raspy, lower-octave voice creates a gentle atmosphere over the top of the heart-racing and nerve-wracking footage of Katia and Maurice gleefully exploring their favorite fumaroles and volatile volcanoes.

“Fire of Love” informs the viewer early on that it will end with the deaths of its subjects in the 1991 eruption of Japan’s Mt. Unzen. By Shakespearian standards, that would make this film a tragedy, but it feels like anything but. Yes, it’s filled with tragic elements including the devastating effects of eruptions, but through Maurice and Katia, we feel the same joy from the exploration of these temperamental parts of the earth that they do.

The film never feels like a straight science or nature documentary, though those were, obviously, the driving forces behind the Kraffts’ work (along with the Earth’s mantle), but the film skips the geology jargon that could lose viewers who aren’t well-versed in earth sciences or its terminology.

Instead, everything said or covered is incredibly straightforward and easy to follow. In fact, it feels like Maurice would have preferred it that way. In one instance, he refuses to classify volcanoes or eruptions in conventional and scientifically established terms. He believes each is unique, so instead, he refers to them as red and gray volcanoes. Red meaning the eruption includes slow-moving lava flows (the “nice” ones as the Krafft’s pointed out), and gray referring to the devastating pyroclastic eruptions that move superheated ash out of the side of a volcano at immense speeds, decimating everything in its path. No mention of eruption types or even of the terms shield or composite volcano.

Though this one example is simple, the Kraffts’ quest for knowledge was not.

Through their stunning footage, we get a glimpse firsthand at the immense danger they put themselves in to learn what makes the earth tick.

Coming alarmingly close to active eruptions, dodging volcanic bombs and thirsting for more data and evidence to help solve the geologic puzzles before them.

“Fire of Love” succeeds in painting a clear, concise vision of the love that surrounded and fired between the Kraffts. They may not resort to outright displays of PDA, but their affections are clear. It’s them and the volcanoes against the world in this fascinating love triangle. The film keeps you engaged in their story, along with the stories of the eruptions they witnessed or whose aftermath they saw.

There are moments when any “normal” heads will be shaking and wondering what would drive two people to camp on the edge of an active volcano, but as the documentary unfolds, we see the results of all of those hair-raising moments. We see it in the conclusions they drew, which helped change the way the world reacts to active volcanoes, and in their zeal for remarkable places most would never dare venture.

Told with the utmost respect for its subjects, “Fire of Love” erupts with heart and is a brilliant example of unconditional love.

On screens this week: The Brad Pitt-led action flick “Bullet Train” races into theaters (check out my review in next week’s GO!), Jo Koy brings us to the table for “Easter Sunday” and “Bodies Bodies Bodies” takes a stab at rich 20-somethings in a remote mansion. Hitting Apple TV+ is “Luck,” an animated film about the unluckiest person in the world finding herself in the actual Land of Luck. The story of the 2018 rescue of the Thai boys’ soccer team comes to Amazon Prime with “Thirteen Lives,” and the action-packed “Prey,” set 300 years ago in the Comanche Nation, hits Hulu.

“Fire of Love”

93 minutes

Rated PG for thematic material including some unsettling images, and brief smoking.

4 stars