Warning - this is not a film you should attempt if you are tired, have a headache or have a severe reaction to out of focus cinematography and non-linear narrative. Persevere though, and you will find that there is much of interest in this dreamlike quasi-experimental film about memory and your perception of it.

Jenny (Daniela Schulz), a beautiful young Goth girl, and Johann (Christoph Bach), a nightwatchman who's prone to nosebleeds, meet one night and start an affair. It becomes apparent that there is some element of deja vu in their meeting, a feeling of inescapable predestination to their relationship. But is this real, or just imagined, and how does all this relate to Jenny's existing life and boyfriend?

From the very start of the film, you are struck by its visual imagination, hinting at an entire life lived drowning underwater. By shooting through sheets of rippled glass, the effect is of a world just slightly warped and out of focus, mirroring the characters' perceptions of their world - unclear, confused and seemingly drifting like sticks in a stream. You quickly become acclimatised to this, and are drawn into the looping, disjointed narrative where situations are revisited and reperceived from different viewpoints.

Additionally the film skews your interpretation of the real world as projected into the film - is there really an isolated fog-shrouded island in the middle of Berlin? In this sense there are elements shared with films such as Eternal Sunshine of the Spotless Mind, another visually striking film which deals with issues of purging memories to reach a more serene ascetic, and Memento, as each new cycle adds more information about the characters and their relationship.

There is an ethereal beauty to some of the shots and a real sense of empathic emotion. Scenes of Johann and Jenny playing in the lake and their subsequent night spent in his island cabin take on subtly different hues as we see more of the backstory. Filming on grainy Super-8 for the "real" world and high-def video for the "remembered" one the effect is of uncovering a bunch of home movie tapes documenting the early stages of your parents' relationship. And yet there is always something more sinister in the background here, which gives us a narrative safety line to follow through the film. Even as it exposes the "reality" of sauna sex-cams and regional Hellfire groups, it hints at something darker and more primeval driving the characters' interactions.

An outstanding example of a film which is uncompromising in its vision, Seven Heavens will leave you confused, maybe unsatisfied but with a sense of having experienced a worthwhile journey - just like a dream.