‘Neap tides are when the moon is halfway through its cycle, so it’s not new or full. The moon and the sun are at right angles to each other. At those times, the forces on the sea are weaker, so there’s not much difference between a high and low tide. So when you get in even at low tide, you can only just touch the bottom.’

‘How come you know so much about all this?’ Maddy asks.

‘I learnt all about the sun and moon when I was sailing,’ Helga says. ‘It’s fascinating stuff. And what’s really weird is that, wherever you sail in the world, the sun always rises in the east and sets in the west.’

‘Really?’ Claire sounds genuinely fascinated.

‘Each day from now, the sun will arc higher across the sky.’ She points up. ‘By the summer equinox in June, the sun will set over there because each day that arc will be shifting to the north.’

‘I’d never noticed that before.’ Maddy sounds thoughtful.

‘That’s why all the birds and butterflies migrate north too – along the path of the sun.’ Helga watched the starlings go last week. They’d gathered in great numbers on the telephone wires and she’d imagined them chatting about the journey back to Scandinavia. How she longs to go on a journey herself.

‘How have I got to nearly fifty and been so ignorant of facts like these?’ Claire says.

‘You know them now,’ Helga says. ‘I bet you know all sorts of stuff I don’t know.’

‘This week I’m learning about planning laws. Not the most fascinating subject,’ Claire says. ‘My bloody neighbour is putting up an extension and …’ She shakes her head. ‘I’m not going to get worked up about it now. This is my break from it, but I’ve become rather obsessed with an appeal.’

‘Nothing worse than horrible neighbours,’ Dominica says.

‘Rob and Jenna. They think they’re so perfect. They’ve got this plan to build a monstrosity on the back of their house, which will take all of our light and overlook us completely, but the worst bit of it all is that they’re going to cut down the cherry tree. I love that tree.’

‘Surely they can’t do that?’ Maddy says.

‘Well, you’d think not,’ Claire replies, ‘but I don’t know how we can stop them.’

‘I know a bit about planning,’ Maddy tells her. ‘Maybe I can help?’

‘Could you?’

‘I’d be happy to try. It’s the least I can do to say thank you for getting me into swimming.’

Helga swims ahead with Dominica leaving them to chat.

‘You’re all right at work?’ Tor checks and Dominica smiles. ‘How’s it been this week?’

‘I had a meeting with my boss,’ Dominica says. ‘He wanted to check in to see that everything was fine now I’m back and to re-instate my targets. He was very awkward about the Chris thing.’

‘You mean, you being bereaved,’ Helga clarifies. Why do people pussy-foot around death?

‘Exactly. You should have seen him squirm.’