In the chaos, I had lost my shopping bags, which concerned me even more at that point than the pain in my knee. I texted Charlie, playing down what had happened, telling her I’d see her at the flat later if she could make it round. Then, finally, I was wheeled in to see the nurse and made to wait some more for an X-ray.

‘You’ve sprained a knee ligament,’ the nurse said, eventually. ‘Nothing too serious, but you’re not going to be able to walk on it for three to four weeks. Are you on your own? Do you have someone who can come and help you get home?’

This was just like when my retina had detached. Except this time, I did have someone who could come and be with me. I called Charlie and told her what had happened.

‘Oh, Andrew! I’ll be right there.’

Two hours later I left the hospital, my swollen right leg swaddled in a tight bandage, on a pair of crutches. I had ten days’ supply of codeine, forty pills, and instructions to rest. ‘For goodness sake, don’t go out on your crutches in this snow and ice,’ the nurse said, looking at me as if she was sure that was exactly what I was intending to do.

Charlie called a minicab which took us home. My street was carpeted with snow and the taxi could barely get up the road, the driver complaining and cursing as he inched his way towards my flat, headlights illuminating the swirling snowflakes. Charlie insisted that he take me to my front door. Then came the worst part: getting up the steps, all four flights. I did it backwards, on my bum, pushing myself up, trying not to bump my leg, shards of white-hot pain exploding every time I did. By the time we reached the top I was almost in tears, sweating and shaking.

Charlie, her face etched with concern, helped me onto the sofa, pushing the coffee table away so I could sit with my leg propped up on a cushion.

‘My poor wounded soldier,’ she said.

‘I need a drink,’ I said.

‘Is that wise, with the codeine?’

‘I don’t care. Please.’

She opened a bottle of red and I gulped down a glassful quickly. I had taken two painkillers at the hospital and they were finally kicking in.

It was so good to have her beside me. What would I have done without her?

‘You really must be more careful,’ she said, smiling gently. ‘I’ve only just got you. I can’t bear to think of losing you.’

‘I’m sure,’ I said, ‘that someone – some bastard in the crowd behind me – pushed me.’

She looked shocked. ‘Did you see them?’

‘No. But I felt hands on my back. I’m sure I did.’ My blood chilled as I thought of it, like the snow was inside the room; inside my veins.