The rest of the evening passed without event, and I woke this morning to another bright, sunny day. I’m excited that we are off to visit the stupas at Bagan this afternoon – one of the highlights of the trip – and I grab a window seat on the coach, relieved when Thea slips into the place next to me. She’s a tall, slim woman with wonderful bone structure that has lost nothing of its beauty as she has aged. Her long silver hair is swept back into a low ponytail during the day, but in the evening it sits resplendent on her shoulders. Some of the passengers come to dinner in shorts, but Thea always wears something in silk, with modern chunky jewellery at her neck. I can’t help thinking that this is how I would like to look when I’m older – elegant but a bit funky.

As the coach pulls away from the river, I fiddle with my bag, making sure it’s firmly closed and attached to some part of my body so it can’t be stolen.

Thea looks at the bag and laughs. ‘Why on earth have you brought that enormous bag with you, dear?’

‘I don’t have a pocket big enough for my key,’ I say. I have wondered a couple of times why the management of the boat has chosen to use such a heavy metal ball as a key ring. It weighs a ton.

She pats me on the leg. ‘There’s no need to bring it with you. We’re stuck with each other for the whole trip, so if anything goes missing the crew will search everyone’s room or call the police.’

‘My laptop’s in there, though.’

‘A little secret, dear: probably every cabin on board has a laptop or an iPad lurking inside. Except ours, of course. People these days seem compelled to share their every waking moment on a blog or on social media, an obsession I fail to understand.’

She gives a little shudder, and I want to ask if she and the doctor have any children. I know people of Thea’s age often use Facebook to keep in touch with their kids. But for some reason it seems intrusive to enquire.

‘Can I ask if there’s something worrying you, dear?’ she asks in a hushed voice.

‘No, I’m fine,’ I answer, but even I can hear the lie in my voice.

‘I don’t mean to pry, but I’ve noticed that sometimes your eyes glaze over as if you’re thinking of something or someone else. And I get the feeling they’re not good thoughts. Am I right?’