The Beyond (film) – From:Wikipedia
Following the release of City of the Living Dead, Fulci decided to continue that film’s exploration of metaphysical concepts — in particular, the ways in which the realms of both the living and the dead might bleed into each other.
Fulci also wanted to do a film that would pay homage to his idol, the French playwright Antonin Artaud. Artaud, a sometime member of the early 20th Century Surrealist movement, envisioned theatre being less about linear plot and more about “cruel” imagery and symbolism that could shock its audience into action.
From Kishmot: But for one slightly flawed action scene his is a top horror movie. It combines the slasher genre with the supernatural and shares a similarity with The Shining in its metaphysics.