‘Look at how this portrait is much more chaotic. You see the smears of paint around the officer and his wife? Those are mistakes or changes Catharina made during the process. Some critics think it indicates a shift in style. They think the disordered application of brushstrokes represents Catharina’s anguished indecision over her wish to sell Sterrenwijck and relocate to France. And, of course, this is the only portrait featuring Catharina’s companion, Anna Tesseltje. There she is, playing the role of devoted bridal attendant.’

As Jeanette moved her hand aside, I leaned forward. My breath caught. There was Anna, stooping low, her fingers grasping the hem of the bride’s silver train. She wore the silk gown, the damask now a familiar shape and pattern, although the colour was different to how I imagined.

‘That’s it,’ I said, clutching Jeanette’s arm. ‘That’s the dress!’

‘Is it really?’ Jeanette said, her eyes rounded in shock. ‘How extraordinary. You’re sure?’

I nodded, too excited and overwhelmed by emotion to speak. My heart had begun to thud and all the details of the room had become softly blurred so that only the dress stood out in vivid clarity, the centuries-old oils that had captured all those fine details in the fabric gleaming in the glow of the downlights. Jeanette and I stood for a moment longer in silent communion, staring at the painting that would never be completed. The dress itself was more of a pure gold, as Liam had suggested, rather than rich reddish-copper. It shone as brightly as freshly churned butter or like the sunlight that fell through a large casement window, casting its matrimonial blessing over the young couple standing in the centre of the wood-panelled library. There was a stiffness in Anna’s posture, and her face, what I could see of it, wore a serious expression. Her downcast eyes were fixed stubbornly on the task at hand and wisps of dark hair spilled from the contours of her velvet cap. She had the glass earrings – the Dutch tears – threaded through her earlobes. Clearly, she had been dressed up to represent the wealth and power of the newly wedded couple – her future employers. Yet there was something unique in the way Catharina had painted her – a vibrancy and solidness, compared to the two washed-out figures at whose feet she knelt – that suggested her loyalty lay elsewhere. I kept waiting for her to raise her head and stare defiantly at us, but she remained static, just a varnished facsimile of a once living, breathing person.

‘You know,’ Jeanette said at last, ‘there’s a theory Catharina van Shurman was in love with a woman. Her name was Margriet Pieterson. There was some confusion in the early days of van Shurman scholarship over whether Griet was actually a man, but her gender has been pretty well established for a while now.’

‘Catharina and Anna Tesseltje,’ I said. ‘There’s nothing to suggest they were involved?’