They strolled along the water’s edge in the mellow afternoon light, talking once more about the old times. But after the jokes about army food and some of the characters they’d known, Ruth – as if she had been needing to say it for some time – came out with one of her sudden bursts of forthrightness.

‘You know, Molly, my family think it’s marvellous, my being at Cambridge and doing science. My mother would have loved to have had the same chance. And it is such a privilege – there’s no more beautiful place, and it’s so old and scholarly. There’s that powerful feeling of all the people who’ve been there racking their brains over things before you. I mean, at Girton, where I am, there’ve been all those brave, pioneering women – so inspiring. Except that thinking about them makes me feel all the more ordinary and inadequate. I’m so grateful for it all, I am . . . But there’s hardly a day when I don’t wish in some ways that I was back with all you ATS girls. Ridiculous, isn’t it? But d’you know what I mean?’

‘Yes,’ Molly said faintly. She couldn’t begin to explain just how much she understood, and how lost she felt now. How she had had a life where every fibre of her felt challenged and involved and useful, whereas now everything felt empty, bewildering and without purpose.

Now Ruth had started, it was like the floodgates opening.

‘Gosh, I hope you don’t mind me banging on like this, Molly. The thing is, I can talk to you. If you’re at Cambridge, especially if you’re a woman, you’re expected to be so grateful all the time. And I am, of course . . . But I can’t seem to communicate properly with anyone. There are other ex-service girls, of course – quite a few Wrens and WAAFs. But somehow we all seem to be on our own as to how we feel about things. Perhaps I’m just – I don’t know . . .’ She made a frustrated movement with her hands. ‘I expect it’s just me. I’ve always felt like a misfit: at school, then in the army and now in Cambridge, as if I’m outside looking in through a window, and everyone inside knows what’s going on and how to behave. Just for a while, a blissful while towards the end of the war, I began to feel I fitted in a little bit, but now . . .’ she ended desolately. ‘My goodness, we’ve got victory and peacetime and so much of what we were supposed to be fighting for. So why does everything feel so flat? I say, Molly – gosh, are you all right? I didn’t mean to upset you.’

Molly’s shoulders had begun to heave and she was full of a bursting tightness, as if a great howl of anguish were trying to escape from her. She began to sob.

‘Oh my goodness, Molly dear – what is it?’ Ruth took her hand and gently pulled her closer to the waterline, away from other people. ‘I thought you were looking a bit strained and peaky, not like your blooming self at all. But I didn’t like to ask.’