Right people... This film is tremendous. I knew hardly anything about it before I watched it & it blew me away.
What mainly grabbed me, is it's utter ferocity & intensity, it just keeps growing & growing as the film goes on (some real turned up to 11 stuff is delivered!) The performances are outstanding, Isabelle Adjani, Sam Neill, Heinz Bennent, all giving seemingly everything they have - blood, guts & gristle. It must be said Isabelle Adjani's performance is particularly outstanding, the metro scene is astonishing, pure, visceral & truly unforgettable.
Even though the genre `horror' seems to be tagged to this film, it is far more than that. The first half portrays a relationship `break down' in such a brutal, grizzly way it brings Lars von Trier's Antichrist to mind (which I'm sure Possession must have been an influence). Science fiction, art house, comedy, noir are all here in buckets & having the Berlin wall overlooking the story is a wonderful idea.
The superb build of the film & answers given heading to the end, gave me a Hitchcockian experience (dare I say... better). The pink socks, the kid, the bath, Sam at the door, Isabelle's look to camera & whatever is happening in the sky.
Again, this film is tremendous. Owing to it's cult & kinda unknown status the price is a trifle more than a standard DVD....... It's totally worth it.