Simultaneously a love story of two vulcanologists and a filmic paean to the variety and power of volcanoes, “Fire of Love” tells the tale of Katia and Maurice Krafft, two scientists who dared to peer closely at volcanoes for three decades, before perishing (when a volcano exploded suddenly) in 1991. Cut and pasted from the Kraffts’ incredible archive of footage and film, the movie evokes the molten, pulsing, unstoppable power of Earth’s crust on the up and away. The two scientists are besotted, with each other and with lava, and their naked, childlike curiosity is electrifying. Sara Dosa’s direction is wonderfully paced and structured, and Miranda July’s voice-over strikes a fine balance between admiration and information. Fire of Love triumphs as both nature documentary and epic of heroism.