Off the motorway, the traffic snaked back solid to the Blackfriars interchange. Frantically I watched the clock, creeping forward incrementally, until I could bear it no longer. Abandoning the car on a broken meter I sprinted through the rush-hour fumes, dodging swearing cyclists and the motorbikes that sneaked down the middle, stumbling over the kerb on Ludgate Hill, until I was falling in panic, unable to right myself. A double-decker bore down on me, horn blaring; a builder in a yellow hard hat snatched me from its path in the nick of time, his calloused hand warm on mine. I was too stunned to do much more than blink at him and run on.

They were closing St Paul’s Cathedral to sightseers as I finally reached the great stone stairs. For too long now my life hadn’t made any sense; I had to know the truth. Someone, somewhere, had to know the truth.

Inside, the internal gate was shut.

‘Please,’ I gasped at the curate, closing up. ‘Please, I have to – I’ve come so far.’

That someone might be here.

‘You look pretty desperate,’ the jolly curate relented, his chin resting on his collar, waving me through with his walkie-talkie. ‘Last one in. This one’s on God.’

‘How do I get up to the Whispering Gallery?’ I wheezed gratefully, leaning on the barrier for a moment to catch my breath.

It took me ten minutes to climb up, and my heart was banging so hard by the time I’d reached the gallery in the huge dome that I had to sit down as soon as I got there. I’d passed a gaggle of Italian tourists coming down the stairs, but otherwise the space was empty. I thought he hadn’t come, the anonymous writer – and I heard my name said softly, and I turned and saw him.

They say that when you’re drowning your whole life flashes before your eyes – though it seems unlikely that anyone could confirm it. True or not, I felt like I was falling backwards now, splashing messily through my own life.

He walked towards me, thin and no longer elegant, wiry-limbed and crop-haired instead.

‘Hello, Rose,’ he said and I tried to find my voice.

‘I thought,’ it came at last, ‘I thought that you were dead.’

Lord Higham had let it be known that his eldest son, Dalziel, had taken his own life, permanently scarred by the tragic and sudden death of his girlfriend, Lena. There was never any formal announcement of the death and the funeral was said to have taken place quietly and privately on the family estate in Scotland. And of course, that suited them just fine.