Astonishing Horror Master piece.
Have seen a lot of films, reviewed a lot of films but this extraordinary two and a half hour technically-perfect humanistic horror film from one of the finest writer/directors in the business (auteur of I SAW THE DEVIL) was something of a cipher.
The closest analog I can suggest in David Lynch's 2001's Mulholland Drive, yet another technically perfect, humanistic, suspense opus which keeps you captivated for its full length, yet has you walking out of the theater shaking your head and wondering what exactly you just saw? Both film-makers understand the "big secret" of story telling which is, if you can present your story in such a way that the viewer feels he or she is sharing the experience with the protagonist, you can tell any story you like and the viewer will just keep going.
I will not even try to provide an explanation for what THE WAILING means, other than to re-quote the writer/director himself who, in numerous interviews on his film, said enigmatically "I began to wonder about the nature of God -- what if he was not always good?" Recommended on many levels. As entertainment, as a puzzle, and as a clinic in how to make a film that engages ... and just won't let go.