Following the progress of two Vietnam Veterans through the soul desert of 70's New York, the film is little more than a handful of fascinating sequences in search of a plot, but holds the interest through offbeat, quirky characterizations and its one-of-a-kind atmosphere. It intelligently avoids any attempt at wider social commentary or 'message' and achieves a genuine, tragic power through chilly understatement and observation. Especially impressive is Gabriel Walsh, who also wrote the piece, as the most sympathetic of the vets. He's a gentle, simple soul who's overwhelming alienation is pushing him toward total breakdown.
The previous poster mentioned the powerful rape-and-murder sequence. This is in no way exploitative, the mise-en-scene (a shabby apartment observed by a distant, unmoving camera) brilliantly conveying the revulsion and horror of the act, and the ultimate hopelessness of it's perpetrators, with incredible power. Also gripping is 'Dancing Dannys' attempted pick-up of Walsh's character. It's beautifully played, tense and finally shocking.
I have an old, rather tatty VHS copy that I picked up in some back-street dive years ago. The advertising blurb and artwork, which includes photographs of scenes that appear to be from a different film altogether, promise an action-exploitation picture. 'Nightflowers', or 'Nightangels' as the ad-art proclaims it, is a far more personal and interesting work than that.