In 1964 Henri-Georges Clouzot, the legendary French director of thrillers such as Wages of Fear and Les Diaboliques, started work on what was to be his most adventurous film to date. L’Enfer (Inferno) was a dark psychological study charting the mental disintegration of hotel owner Marcel (Serge Reggiani), consumed by jealousy at the supposed infidelity of his pretty, flirtatious wife, played by the vivacious Romy Schneider, then one of France’s most bankable stars.

Sadly, the film was never to be. Following catastrophic delays in the production schedule, budget problems and a walk-out after three weeks by Reggiani, already tired of the director’s endless perfectionism, finally a heart attack suffered by Clouzot on set put paid to the ambitious project.

Noted film restorer Serge Bromberg and co-director Ruxandra Medrea have done a wonderful job in piecing together the fragments of Clouzot’s lost film, not least in persuading his widow, Inez, to give them access to the missing 185 reels, which are mostly without sound.

Clouzot’s main action was shot in black and white and Bromberg fills in the gaps in the script with readings of five scenes with Berenice Bejo and Jacques Gamblin taking the roles.

But the real joy of this documentary lies in the extraordinary and intensely-coloured test shots that Clouzot intended to symbolise Marcel’s disintegrating mental state.

Clouzot conceived a whole battery of hallucinatory effects, jarring camera angles, inspired use of mirrors and auditory distortion to launch a new way of filmmaking. Schneider is bathed in a series of kaleidoscoping lights twisting her features, two actors’ faces are morphed together, anticipating Ingmar Bergman’s Persona, and most stunningly Clouzot toyed with the idea of colour reversal, which would turn blue water blood red but required the actors to paint themselves green to retain their normal skin tone.

In the end it all proved too much. Reggiani left claiming a nervous disorder and the production was already on the verge of collapse before Clouzot’s fateful but thankfully non-fatal heart attack.

Whether Inferno would have become a masterpiece we will never know – Bromberg suggests not. French film critics had already derided Clouzot’s meticulousness as old fashioned, which may have contributed to the director’s mental malaise.

In 1994, the film was remade by Claude Chabrol in typically chilly fashion, but his cold and slightly hysterical retelling doesn’t match up to the psychedelic menace of Clouzot’s vision, brought back to life so magnificently here.

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