‘See, I’m here now, Emily. Let’s hold hands, I bet you’re chilly.’

As she places her hand in mine, I check her radial pulse. High, though her skin is cold and clammy. Is that from the water or something more serious?

I want to get her onto my lap to warm her up but first I try to work through the CABCDE checklist. It’s hard to angle the head lamp to see much, so my ears and sense of touch have to substitute for my eyes. Even off-duty, I automatically assess everyone I meet, in queues or at the pub: eyes, complexion, gait can tell me so much. But now I am literally in the dark.

The sequence will keep me focused. Catastrophic bleed? Nothing external, as far as I can tell . . . but as I touch her abdomen, Emily screams.

‘Emily, where does it hurt? Show me, with your hand?’

I hold on as she runs her hand over her body: her left ankle, left hip . . . ‘It hurts the most here,’ she says, and her fist tightens around mine over her lower rib, on the left.

Ruptured spleen. If I’m right, she needs surgery to stop the bleeding before she goes into hypovolemic shock – unless she has already. But I can hardly operate in a ditch. All I can do is try to keep her stable until someone comes.

‘I’m going to put my arms around you for a nice cuddle, OK, Emily? So we can keep each other nice and warm.’ It hurts my shoulder, but she stays silent, so I guess it doesn’t hurt her. ‘What happened, Emily?’

‘The train . . . went all wonky . . . I was with Grandma and . . .’ She starts to cry.

‘Don’t cry, sweetheart. You’re safe now.’ And crying makes your breathing worse. ‘Tell me how you ended up falling over.’

‘There was a hole in the train . . . I climbed through it but it was all dark . . . and my glasses got broke . . . grown-ups were crying . . . it was scary so I was running and it looked like people . . . but I . . . slipped.’

‘How long ago?’

She doesn’t respond.

‘Stay awake, Emily. How long do you think it’s been since you fell?’

‘I don’t know . . .’ She starts to cry. I don’t want her to waste energy.

‘What songs do you know, Emily?’

She tells me a few titles I don’t recognize. My interest in music stopped the year I started med school. I try to remember songs Marilyn’s children like, and as I picture Ava, fear seeps through me, as chilling as the water.

Don’t be such a flake, I tell myself. Of course you’ll see them again. My career might be DOA because I’ve been such an irresponsible fucking idiot, but I will make it out of this ditch, and so will Emily.

‘What about “Happy”?’ I suggest.