Nicolas Cage in "Mandy" Sundance Institute

Panos Cosmatos’s unforgettable Mandy is a midnight movie that should never be seen at midnight. It requires active viewership, even as it envelops you in its extreme moods. I can’t imagine how I might have responded to it at a late hour, even though it is playing in the Midnight section here at Sundance; I saw it in the middle of the day, and as I walked out into the bright street afterwards, the world felt like it had changed. (I realize that a lot of people had a similar experience with Cosmatos’s previous effort, Beyond the Black Rainbow, a film I found mostly inert and tedious.) More than a story, Mandy offers large blocks of mood and emotion in which to luxuriate — until you can’t. Cosmatos’s visual style borrows from psychedelia, Frank Frazetta illustrations, J.M.W. Turner paintings, and the way oil and blood swirl in puddles of mud.

The plot is a loose one, and to describe it wouldn’t mean much. (Though, full disclosure: the film’s co-writer, Aaron Stewart-Ahn, is a friend of mine.) Let’s just say that Nicolas Cage is a lumberjack deeply in love with his wife, Mandy (Andrea Riseborough), and that she’s coveted by the leader of a stoned-out cult, who has an army of demon bikers at his beck and call. Cage’s character is at peace in the movie’s first half and full-tilt bloodthirst crazy in the second — and I took very little pleasure from his nuttiness even as the actor goes admirably all-in. I don’t think we’re meant to, because Mandy is heartbreaking: There’s one lengthy close-up right around the middle when we see the light literally go out from Cage’s eyes.

So, Mandy is a revenge movie for people who don’t like revenge movies. All too often, films like Death Wish and its ilk indulge our fear and our hatred — our deep, visceral, nihilistic need to destroy things. We’re just waiting for the violence to start. But with its deliberately paced, mesmerizing and sensuous first half, Mandy grounds itself in the idea of desire and peace, and their subsequent loss and perversion. And it also suggests that the only thing keeping the world from turning into an unholy carnage fest is the power of love. The film’s two sides — the soft, textured reverie of its first half, and the surreal, angular savagery of its second — exist in perpetual balance; one would die without the other.