'The Whip and The Body' (1963) – Mario Bava.

It could be argued that one of maestro Mario Bava's most visually sumptuous and preternaturally perverse horror films is the deliciously deviant Ernesto Gastaldi scripted Sado-Gothic classic 'The Whip and The Body', a sinfully sublime crepuscular creep-fest wherein towering terror titan Christopher Lee, is at his sinister subdued best as the beastly, eminently degenerated errant son Kurt Menliff who doomily returns to shadow-slaked Castle Menliff in order to reclaim patrimonial rights and catastrophically re-ignite dangerously incandescent passions of his dusky-haired paramour Nevenka (Daliah Lavi), now in a lukewarm marriage to his rather pallid brother Christian (Tony Kendall) which very soon heralds a multitude of macabre murders, lashings of morbid terror trysts, deep-seated diabolical familial discords, eerie masochistic ministrations from beyond the grave, mood-master Mario Bava's ghostly Gothic Giallo is a beautifully illuminated, scintillatingly sadistic phantasmagoria heightened with a truly mesmeric performance from sultry siren Daliah Lavi. A criminally underrated celluloid nightmare, certainly no less haunting than Jack Clayton's 'The Innocents' (1961) or Roger Corman's similarly necromantic 'The Tomb of Ligeia' (1964).