Nancy was the first to see it. A man – six feet tall, with shoulders almost as broad – had leaped out of the alcove next to where she and Billy were sitting. It took him a second to push through the girls swaying to the Latin rhythm on the edge of the dance floor, and another second to paw his way through the dancers turning their hypnotic box steps on the floor itself. By the time Billy had realised what was going on, the first punch had already been thrown. The man, with his shirt sleeves rolled up to reveal dockland tattoos up and down his forearms, was carving Raymond de Guise and Hélène Marchmont apart, bellowing at them.

The band played on.

Through the music, Nancy heard the man screaming: ‘Thought we wouldn’t recognise you, Ray? Thought we’d have forgotten your face? You’ve been seen in the neighbourhood, mate. But you’re not welcome, you understand? None of your lot are welcome.’

A clenched fist connected with Raymond’s jaw and he went whirling backwards. The couple who had been dancing behind him were the only thing that stopped him crashing to the floor. By accident they caught him and set him back on his feet – but, by then, the brute had readied himself for another unrelenting strike. He brought the back of his hand across Raymond’s jaw, then drove the other clenched fist into his stomach. Raymond doubled over, dropping out of Nancy’s sight. In the crowd, Hélène Marchmont screamed.

Only then did the bandleader realise what was going on. The music ended sharply, in a chaotic mess of trombone and dying tenor horn.

In an instant, Nancy was on her feet. Billy cried out – ‘Nance, no!’ – but, if Nancy heard him, she paid it no mind. She staggered through the dancers flocking away from the dance floor. In their haste to get away from the tumult, they seemed to have formed a cordon blocking her path.

‘Raymond!’ she screamed, but Raymond was not the one to hear. Hélène Marchmont looked around, saw Nancy, and her face creased in surprise.

Nancy wasted no time. This was not the moment to care about whether Hélène and Raymond were lovers or not. She forced her way through the wall of dancers, just in time to see Raymond fall beneath another clenched fist. Then the huge man was on top of him, pounding at his face. Between each blow he took a breath, as if to ready himself. And all the while he was crying out, spittle flying from his lips.