Werner Herzog has had a long and very prolific career as a director, encompassing both fiction features and, especially of late, a huge number of documentaries both long and short. But despite this profusion of films, he is still remembered, for better or worse, for the strength of his five collaborations with the actor Klaus Kinski, all of which are contained in this remarkable box set. Even calling Kinski an actor is somewhat misleading -- he's more akin to a force of nature, and these five films are equally famous for their raw onscreen intensity and for the often rocky circumstances of their creation. At least one rumor suggests that Herzog was once forced to pull a gun on Kinski to threaten him into performing, and the tense relationship between director and star was compounded by the wild locales in which the films are set.

"Aguirre: The Wrath of God" is a hallucinatory fable about a rebel Spanish conquistador who takes his troops off in search for a legendary city of gold, leading them instead to their deaths in the middle of a hostile rain forest environment. Kinski is volcanic in the title role, and Herzog perfectly captures the humid, oppressive atmosphere hanging over this ill-fated expedition right from the beginning. This first collaboration between the duo was legendary right from the start, and it culminates in a famous scene where the wild and increasingly insane Aguirre, the last survivor of his decimated crew, stands on a raft swarming with scurrying monkeys, ranting into the jungle.

This fascination with doomed men setting impossible goals is carried over into "Fitzcarraldo," with Kinski once again in the title role as a man so obsessed with opera that he plans to pull a steamboat over a mountain in order to bring an opera house to the Amazon. Herzog loved filming in these fierce jungles and wild river rapids, and he insisted that the film's central moment, the boat being propelled over a mountain, should be realistic, not achieved through any special effects. These scenes thus have a very raw physicality, and one can feel the stress and power of the physical processes involved in leveraging this boat up steep inclines and back down the other side.

More humble and constrained are "Woyzeck" and "Nosferatu," which are equally deranged in their intense emotional content but much less physical. The former has Kinski as a cuckolded soldier who's driven insane by his fickle wife, and is finally driven to murder. The whole movie, adapted from a stage play and correspondingly confined in its sets and characters, is intense and claustrophobic, never more so than in the absurd opening titles, which feature a wild-eyed Kinski doing push-ups.

Herzog's remake of the silent vampire classic "Nosferatu" is relatively faithful to the original but amps up the moody, languid atmosphere and the subtle, creeping terror, creating a vampire film in which everyone, monster and victims alike, seems to be sleepwalking. Kinski, of course, plays the vampire, and there has never been a more frightening movie monster, or a more perfect role for the unhinged actor. He is the ideal actor to capture the unsettling sexuality and sensuality that is inherent in the best vampire stories.

The final Herzog/Kinski collaboration was "Cobra Verde," and though it's not as successful as the other four films, it's still very interesting. Kinski plays an adventurer who is slowly driven into corruption and insanity as he becomes a slave trader, and it's a curious film that mostly stands testament to Kinski's weird animal magnetism. It's impossible to take one's eyes off him, no matter what he's doing.

This excellent box set is, finally, rounded off by the inclusion of "My Best Fiend," Herzog's documentary about his torrid on-set relationship with Kinski, with whom Herzog apparently shared intense love/hate feelings. Herzog uses this documentary to relate many of the most sensationalist and legendary stories about Kinski's on-set behavior and the great lengths the director sometimes went to restrain him. The result is a film that's both funny, unbelievable, frightening, and even strangely moving -- much like the five features the duo made together. This is an absolutely essential box set for those interested in either Herzog or Kinski, or for that matter in the cinema itself. For this was one of the most provocative and productive collaborations in cinema history.