She’s probably waking up about now, I think, jumped on by her daughters, brought tea and toast by Warren, in the life she moulded for herself when she ran towards life – a whole and happy one. Can Dad and I join her there? Can we make the trip to Nova Scotia? Could we wake up in Albert Bridge, too, wander down to the quay, eat pancakes at Missy’s Diner (I’ve been googling) and sip afternoon tea on the swing chair on the veranda while the nieces I’ve shamefully ignored play at our feet? Could we sit and talk to Angela on that veranda until dusk falls and everything we want to say has been said? Maybe we could. Maybe we could re-create the little family we once knew and wrap our arms around its new members. I also wonder if Angela’s going to sit on that veranda later today and make a call to the British Embassy in Stockholm, looking for our mother.

‘Is the sign still there?’ asks Dad.

‘What sign?’

‘The sign about soldiers breaking their step. You’ll see it on the tollbooth.’

We are almost at the bridge. The river is busy – boats and barges and a couple of pleasure cruisers, their windows glinting in the unblinking sun, glide under the bridge in both directions. We arrive at the left tollbooth of an octagonal pair standing sentry at the gateway to the bridge. There’s a Royal Borough of Kensington and Chelsea sign on one of the panels, in pink and purple.

‘Albert Bridge Notice,’ I read out. ‘All troops must break step when marching over this bridge. Why was that, then, Dad?’

‘Bad vibrations.’

‘Eh?’

‘Walkers have a natural tendency to match their steps to each other, and when they all walk in unison it causes vibrations. It happened at the Millennium Bridge, when it opened – remember? Pedestrians fell spontaneously into step – thousands of them – and everything got a bit wobbly.’

‘Yes, I remember. Oh, that’s interesting.’

What did the troops do instead of marching? I wonder. Saunter, hands in pockets? A little light whistling? Did it unnerve them not to march in time with each other?

We’re on the bridge now.

‘Let me tell you about all the boats on the Thames this afternoon,’ I say to Dad.

‘Go for it.’

‘Well, they’re mostly barges – low, flat-bottomed affairs; a couple of tourist cruisers – blue and white, with lots of windows, the sun reflecting off them; some small motorboats; the river police … a big brown dog on the back of some sort of dinghy …’ I’m reminded yet again of Kemp’s houseboat, how many of my emotions were contained in that thing. ‘There’s also an old-fashioned tugboat, red and black, complete with a seagull perched on its cabin and a man in a woolly hat.’