There’s a busker at the end of the tunnel, by the tube entrance, gruffing along to ‘Wonderwall’, with an accompanying mournful guitar. As the children pass him, he segues into ‘Twinkle Twinkle Little Star’, and starts to sing the nursery rhyme gently, plucking at the guitar like it’s a lute. A child to the front of the snake joins in, lending his high, slightly out-of-tune voice to the husk of the busker’s, and then another and another adds their voice – an escalating symphony – until the sweet pure voices of the children completely mask that of the busker and swell in the cool, echoing chamber of the tunnel. As they walk in time, now, to the music and sing so joyously, I breathe in the sweet sound of those voices like honeysuckle and I glance across at Dad and he is singing too – so softly I can barely make out the words – and he has tears in his eyes and I have tears in mine. And we’re in step now, too, with the children, and as I also lend my voice to join in with this nursery rhyme that is as old as the hills and worlds far beyond them, one of the children turns from the tail end of the snake and holds her hand out to me, fingers spread, as though she is trailing them through a rippling stream, and she smiles at me, her face lit up like a beacon as though mine is – amazingly – a beacon to her, too, and I smile back, through my unchecked tears.

CHAPTER 21

When we get back to Chalk Farm, standing on the pavement outside the brown doors to The Palladian is a young man holding a blue plastic file and standing next to him is Kemp.

‘Hi, Bertie,’ says Kemp as we approach, and I remember I never replied to his final text, outside the Dickensian. ‘This is my nephew, Ryan.’ He gestures to the young man to step forward and shake Dad’s hand. ‘I promise you we have a reason for being here and I’m not just randomly loitering in the vicinity of your flat again.’ He grins at me. I shake Ryan’s hand and look at Kemp quizzically. ‘Ryan’s interested in The Palladian.’

‘A little young to be a property shark,’ I quip, thinking of all those brochures from speculating estate agents.

Kemp laughs. ‘He’s doing a sixth-form project on Leslie Green, the tube station architect,’ he explains. ‘I told him I knew someone who lived above one of his stations.’

‘Leslie Green didn’t actually design the flat,’ I say. ‘The Edwardians did.’

Kemp raises his eyebrows. ‘No, but is it OK? If we come up and take a look around? Just a swift one? Ryan was too shy to come and knock on his own.’