The principal credit in this chilling low-budget thriller/horror storyprobably should go to Time Krabbé who wrote both the screenplay and the novel "The Golden Egg" on which it is based but director George Sluizer does a commendable job by keeping rigorously focused on it.
He opens the film in a low key as we are introduced to Rex (Gene Bervoets)and his girlfriend Saskia (Johanna ter Steege), a young Dutch couple just arrived in the South of France for their holidays. They pull in to a petrol station where Saskia disappears without a trace. We then cut to three years later and Rex is still looking for his girlfriend because her kidnapper (Bernard-Pierre Donnadieu) who we saw acting suspiciously at the petrol station, keeps sending him postcards, tantalizing him asw to whether she is dead to alive. The third part of the film brings rex and the kidnapper together and we find out what happened to Saskia.
The Vanishing might be called an essay on the banality of evil and what makes it so effective is that it keeps everything, from actors to action, firmly within the ordinariness of the world it depicts. It is only when we have seen the entire film that we understand the skilful artifice that has gone into it with the three main characters locked in what is a simultaneously inevitable and accidental chain of events, something which might be called the core idea of the film. The ending is truly the stuff of nightmares - a harrowing finish to a inexorable journey.
FYI: Sluizer remade The Vanishing in an American version in 1993 with abysmal results..