No, Quinn could never forgive that slap. Whatever befell the character in the unfolding drama – and Quinn was certain there would be many and terrible consequences – he had brought it all upon himself with that single act of violence.

But Quinn knew the blow was borne out of impotence. He knew that the cavalry officer was in thrall to her. That the only way to free himself from her was to destroy her.

He himself had felt everything that was expressed in that brooding presence.

And so the film began with a rift between the lovers. In the scenes that followed, set in a city Quinn took to be Vienna, the soldier threw himself into what was clearly meant to be a life of debauchery, indicated by the presence of dancing girls, seedy gambling parties and drunken brawls. It didn’t surprise Quinn to see the brunette he had noticed outside among the troupe of semi-naked dancers. The man he had associated with her cropped up too, as a card sharp. He was given a scene in which he upturned a table and threw a punch, only to be horse-whipped by the officer.

Meanwhile, Eloise – or rather, the character she was playing – took to the stage and pursued a career in the dramatic arts. And it seemed she was a great success. Garlands were hurled at her feet. She was shown in her dressing room after a performance as Cleopatra, surrounded by the gifts and cards of admirers.

Quinn’s expectation was that her former lover would come to see her in this part, and a resolution effected. But this possibility was not fulfilled. She was visited and wooed by an aristocratic-looking man, who turned out to be the Count of Somewhere or Other. Quinn wondered if it was significant that the man wore a monocle, which he removed to gaze upon Eloise? He did not remember seeing this actor outside. Presumably the cast was mostly foreign, and not all of them had been able to travel for the London premiere.

The storyline reverted to Eloise’s former lover, whose descent into ruin and disgrace had evidently progressed. A title screen informed the audience that he had lost his fortune and been forced to resign his commission from the army. When the camera caught up with him, he was living the life of a penniless drunkard in a cheap boarding house. There was a scene in which his rapacious landlord – a crudely depicted Jew – came after him for the rent. An argument at the top of a steep flight of stairs resulted in the impoverished drunk pushing the Jew downstairs. The percussionist had fun matching his drum beats to the actor’s tumble. The strings came in piercing and high, a wash of melodrama. The Jew was dead.

The disgraced cavalry officer fled the boarding house in panic, having first helped himself to the coins in the dead man’s pockets, and the bank notes from his safe.

As he trudged the banks of a river, which Quinn presumed to be the Danube, a gigantic pair of eyes appeared in the night sky, looking down on him. They were the accusing eyes of his erstwhile lover. Quinn could not help thinking of the way he had been similarly haunted by Miss Dillard’s eyes, after the unfortunate incident outside Miss Ibbott’s room.

To escape this relentless recrimination, he took refuge in a beer cellar and bawdy house. But the eyes pursued him, and were cleverly superimposed over the eyes of every woman he encountered. Even the prostitute who led him up to a squalid bedroom. She lay back on the bed and looked up at him with Eloise’s eyes – in fact, she had become Eloise. There was only one thing he could do. Quinn understood instinctively. In fact, he felt his own hands tightening as the murderer’s caress turned into a stranglehold. The woman writhed and died in his hands, and in another clever camera effect, Eloise melted back into the coarse-faced, dull-eyed prostitute.

The band whipped themselves into a frenzy as the killer made his escape.

And then the shocking revelation: the camera returned to a close up of the prostitute’s face; both her eyes had been removed.

There were screams from the audience. Even Quinn felt his heart quicken in shock. The cello and double bass hacked a jagged, tuneless seam of notes out of the black abyss.

The music then became abruptly celebratory. Something about it suggested the tolling of church bells.

It seemed to be snowing. And then the snow was revealed as confetti.

Eloise was coming out of a church, newly married to the Count of Somewhere or Other. Her eyes were hidden behind a bridal veil.

A shadowy figure attached itself to the edge of the crowd of well-wishers. Quinn immediately recognized the former cavalry officer, though his appearance had undergone another transformation. He was heavily bearded and wearing dark-lensed spectacles, as well as a homburg and cape. But Quinn’s training enabled him to look beyond the surface details. He could tell by the physique and gait that it was the same man. Besides, the band gave the game away by playing the killer’s theme.

The couple climbed into an open carriage. The camera picked out the sinister onlooker among those celebrating their departure. The bride’s former lover had moved into broad daylight now, so it was possible to see that he was dressed in well-tailored clothes that gave the impression of affluence; certainly he no longer cut the disreputable figure of a drunkard. The money he had stolen from the Jew had evidently enabled him to set himself up. Ironically, the full beard gave him a distinctly Jewish appearance and he looked strikingly similar to the man he had murdered. For the first time Quinn wondered if the landlord and the cavalry officer had both somehow been played by the same actor. He supposed it must have been possible.

The carriage pulled away with a lurch. The camera watched it into the distance. The sense of peril was suspended momentarily as a brief, cheery scherzo played. But the sequence closed with a reprise of the killer’s face. The scherzo fell apart into a low, inarticulate rumbling of dread.

The film caught up with the newly-weds in a train compartment. The groom was reading a newspaper. An inter-title flashed the headline to the audience: POLICE IN DARK OVER GRUESOME MURDERS. VICTIMS’ EYES REMOVED.

Sensing his bride’s interest in the morbid article, he hurriedly folded the paper away and began to make love to her, with kisses on her hands, wrists and neck. Her eyelids fluttered in delight. The audience was once again treated to a close-up of her magnetic eyes.

A ticket collector entered the compartment. Quinn recognized him immediately as the cavalry officer, although his beard was now trimmed into an imperial. Some nagging rationality questioned how he came to be here, dressed in a ticket collector’s uniform, but Quinn realized that he had to accept the logic of the motion picture. Things only had to be shown to be made possible. The literal consequence of events, one thing happening after another, was more persuasive than any notion of cause and effect. Nothing caused anything. It simply led to it.

He was watching a dream, he realized. And if he accepted it as that, then whatever happened in the darkness made sense.

For example, there was no point in asking, How was it possible that Eloise did not recognize the man she had once loved? By the conventions of the kinematic picture play, it was enough for a character to put on a false beard for him to become utterly unrecognizable.

Of course, the real point, as Quinn instinctively grasped, was not that Eloise had once loved the cavalry officer, but that she still loved him. That she would always love him, no matter what he did. That was evident in the first frames of the film, those which showed her eyes in extreme close-up. It was also, by the logic of melodrama, the reason why her lover had had no choice but to strike her and precipitate their separation.

All of this made absolute sense to Quinn.