I wondered why Frank, who must have speculated about it when considering if he'd fathered another son, hadn't asked me to get a photo to check on the possibility of physical resemblance between himself and William Heysen.

With an abrupt gesture Catherine Heysen pushed the photos aside. 'Tell me this-do you look like your father?'

She had me there. I didn't, not in the least.

My expression told her what she wanted to hear. She made an expressive movement with her hands. There was something compelling, almost magnetic about her and it was easy to see how she'd coined it as a photographic model when younger. She could probably still make a go of it advertising certain products. I wasn't going to lose sight of the main question, but now that this matter had been opened up I thought I might as well pursue it.

'Your husband was a doctor. Wasn't he surprised when you got pregnant so quickly and had the child so soon?'

'William was late and large. He had to be induced. The time was.. credible.'

'Heysen didn't know about Frank-that they'd… overlapped?'

She shook her head slightly; the shoulder-length, glossy dark hair shimmered and she smiled. 'My mother was Italian. I favour her as you can see. So does my oldest brother. The next brother favoured my father, who was Anglo. He was delighted and my husband-Gregory- spoke of hybrid vigour. William has blue eyes and his hair lightened as he grew older, although his skin is more olive than fair. Just a bit.'

Was there an edge of contempt in that? A sourness in her smile? I thought so. I was learning more about her all the time and the bits of knowledge seemed to contradict each other. Her self-control and confidence were almost complete but the mention of her son had opened a small chink in the armour. She was vain, with reason to be, but I had a feeling that her beauty hadn't made her happy. Ever.