It was one of a number of British horror films of the sixties to be scored by avant-garde composer Elisabeth Lutyens, including several others for Amicus.

In modern-day London, Christopher Maitland, a collector and writer on the occult, is offered the skull by Marco, an unscrupulous dealer in antiques and curiosities.

In real life the Marquis de Sade's body was exhumed from its grave in the grounds of the lunatic asylum at Charenton, where he died in 1814, and his skull was removed for phrenological analysis.

The Monthly Film Bulletin wrote: "A graveyard opening, followed by the cleansing of the skull in a decor which establishes a nice line in drawing-room laboratories, promises a 19th century piece of macabre skullduggery in familiar idiom; but the opening is merely a resumé of the skull's history, and the main action takes place in contemporary decor which is unusually vivid and imaginative.

But except for one shot towards the end when, through boldness in bringing the thing into close-up, suspension wires are too clearly visible, the mobility of the skull is very well contrived; and such blemishes are small price to pay for an unusually deft piece of macabre supernatural, the impact of which is given extra distinction in Bill Constable's art direction and Elisabeth Lutyens' score.