Those calls where I made a difference used to be enough, but over the last year – longer, if I’m really honest – the rest of it has been getting to me: the hoaxers, the time-wasters, the mental-health patients whose voices I recognize because they call so often and never get the help they need.

‘And that’s enough for you? It sounds so . . . removed.’

Her question stays in my mind as we stop at the second village and I watch the children being checked. It won’t leave me even after we get back to base. I don’t own up to Tim about where I’ve been. It’s better for him not to worry about me.

‘I love this work,’ he says as we sit on the steps of our shared dorm building, sipping chai. ‘People are bored by statistics, but it’s where the nuggets of wisdom are hidden. You can see from the figures that analysis can save more lives than individual doctors.’

‘And you don’t mind not having the patient contact?’ I think of the yearning I felt earlier to hold one of the children.

He shakes his head. ‘What if I could help hundreds, thousands of people, instead of one? I know it’s not as sexy. You don’t get grateful relatives buying you chocolates. But if it works, then who cares?’

Tim looks different tonight. His eyes are brighter and he’s smiling more, his hands swooping as he explains the improvements they’ve made here, the work there’s still to do.

I feel different myself: travelling, experiencing how other people live, even seeing Tim lit up for the first time in . . . well, months.

I realize something as he talks. At home, I’ve stopped seeing him as Tim, my funny, eccentric first-aider and best friend. Instead, I’ve been blaming him for the decisions I’ve made. Yes, I made sacrifices to help him, but that was still my choice.

When did my negativity begin?

Marilyn’s wedding, after that kiss with Joel. I allowed a man who betrayed me to poison my present and future, as well as my past.

What a spoiled brat I am, holding Tim responsible for how disappointing my life feels right now. I am twenty-one years old. It’s about time I got my shit together.

‘What?’ Tim says. ‘You’re looking at me very strangely.’

I don’t plan it, but I find myself leaning over to kiss Tim, his lips still hot and sweet from his tea.

He kisses me back.

The next morning, my head is all over the place. Tim and I didn’t have sex last night – there’s nowhere private enough. Still, I felt closer to him than I have in months.

‘You’re very quiet, Kerry. Worried by my driving?’ she jokes.