Cinema is littered with great collaborations, artistic symbioses that have defined eras and styles. But the one between Werner Herzog and Klaus Kinski transcends collaboration and enters the realm of pathology, of a Faustian pact, of a mutual possession that lasted five films and left an indelible mark on the imagination of New German Cinema. Kinski, My Dearest Enemy is the survivor's attempt to explain the storm. Eight years after the death of his favorite actor, his “dearest enemy,” Werner Herzog returns to the scene of the crime—Peru, the Amazon jungle, the dilapidated apartments of Berlin—to evoke the ghost. He does not do so to appease him, but to understand him, and to explain to us why it was necessary to endure the hurricane.

Herzog is ruthless but honest in constructing his subject. Through archive footage (much of it unpublished, shot by Herzog himself on set, like an ethologist studying an alpha predator), we are presented with an image of Kinski not as an actor but as a medium for a primordial fury, an “elemental” of chaos. The now legendary sequence of the monologue “Jesus Christ Savior,” where a demonic Kinski, identifying himself with the Messiah, harangues and insults a speechless student audience, is not presented as a bizarre anecdote; it is the key to understanding. Kinski did not portray anger; he was anger, an open channel to hysteria. Herzog, with his calm, hypnotic, almost funeral-like voice (the only weapon that could counter that hurricane), explains that his job as a director was not to direct Kinski. It was to channel him. He was the lightning rod that attracted Kinski's electricity and directed it towards the camera lens, hoping not to be charred in the process.

The documentary draws heavily on the five films that defined their partnership: Aguirre, the Wrath of God, Nosferatu the Vampyre, Woyzeck, Fitzcarraldo, and Cobra Verde. Herzog forces us to reinterpret those performances—which are among the greatest in the history of cinema—in light of this new awareness. The rage of Lope de Aguirre, the empty, suffering gaze of Woyzeck, the titanic madness of Fitzcarraldo: these were not performances. They were documentation. Herzog had the genius (and recklessness) to put a man on the verge of permanent nervous collapse at the center of productive endeavors that were themselves on the verge of collapse. The tension we see on screen is not fictitious. It is the real tension between the director, the actor, and a jungle that wanted to kill them both. The documentary confirms what we had always suspected: to bring a ship up a mountain in Fitzcarraldo, you needed one madman (Herzog) to dream it and another madman (Kinski) to embody it.

Kinski, My Dearest Enemy is also a masterful and necessary act of self-mythology. Herzog, appearing in the dilapidated apartment he shared with Kinski at the beginning of their careers, or walking among the ruins of the Amazonian sets, is not a mere narrator. He is the survivor, the Homeric hero returned from Ithaca who tells the story of Polyphemus. The now famous anecdotes about his threat to shoot Kinski (and then himself) if he left the set of Aguirre, or about the (apparently serious) plans of the natives on the set of Fitzcarraldo to kill Kinski because he was an unbearable burden, are not just “behind the scenes.” They are the construction of the Herzog legend: the director as conquistador, the artist as a rational mystic who is willing to do anything, even murder-suicide, in the name of the “ecstatic truth” (the Ekstatische Wahrheit) that only cinema can capture. The film is his version of events, his justification.

The original title, Mein liebster Feind (literally “My dearest enemy,” where “Feind” has an almost demonic assonance), perfectly captures this paradox. Herzog makes no concessions to Kinski's monstrous nature, his abuse, his tyranny on set (the testimonies of co-stars Eva Mattes and Claudia Cardinale are chilling and necessary). Kinski was a despot, a pathological egocentric, a “parasite” (as Herzog defines him). Yet the documentary is, at heart, a love letter. It is an acknowledgment that without Kinski, Herzog's cinematic universe would have been deprived of its black sun, its most unstable and brilliant star. The unforgettable final sequence, in which Herzog shows us previously unseen footage of Kinski in the jungle, playing tenderly, almost sweetly, with a butterfly, is the emotional coup de grâce. It is Herzog telling us: "See? There was this too. There was a fragile innocence inside the monster." It is a complex epitaph, an essay on the dual nature of genius, and the definitive chronicle of one of the most dangerous and fruitful battles in the history of art.