The motorbike was ancient, its exhaust shot, its powers of speeding away pretty laughable. But it was able to pull beyond us before I could grab the briefcase back, and, as it flickered around the assembled crowd, I knew I couldn’t catch it up.

Other than meeting my friend Xander there’s not much my first year at boarding school has been good for, apart from learning how to play this game they call ‘roofs’. It’s banned and therefore popular, and involves throwing a tennis ball from the yard up onto the roof of our four-storey boarding house, the idea being that the next boy in line has to catch the ball when it comes down. That sounds simple, but the house is an ancient Victorian relic, and its roof is made up of all sorts of pitched hips, gables and buttresses. Throw the ball high and accurately enough and those weird slopes become a pinball machine, making it pretty hard to catch. Throw it even higher and you might break a slate, which is why the game is banned, and accounts for four of the six detentions I had in my first term.

As the motorbike wove its way through the crowd of bewildered passengers and clamorous hawkers, I realised I was still holding one of the golf balls I’d picked up from the spilled trolley. There was no way I could hit the bike, driver or passenger through the throng. But the road swept close to the side of the brick-built terminal building just beyond the crowd, and before I knew what I was doing I’d unleashed that golf ball with a year’s worth of tile-busting roofs practice straight at the wall. Golf balls bounce hard. The one I threw was still flying level when it hit the bricks. I got the angle right: no doubt it was a lucky shot – Amelia wasted no time telling me that afterwards – though it must be said that I have a good arm. Either way the golf ball struck the guy driving the bike in the face, hard enough to make him lose control. He swerved into the kerb and both men fell off. By the time I’d made it through the crowd the driver was back astride it, revving hard. His passenger had to run and jump to make it back onto the saddle.

He’d dropped the briefcase in the crash. I picked it up and returned it to Dad. Subsiding adrenaline left me shaky as I did this, but it wasn’t just the aftermath of having sprung into action that made me unable to meet Dad’s eye, having done something so obviously helpful. Weirdly, my achievement made looking straight at him even harder than usual. The awkwardness itself wasn’t new; I’d not been able to face Dad properly in a long while.

‘Thanks!’ he said. ‘My passport, laptop, all our money. How brilliant of you, Jack. What an amazing …’ He tailed off. Though I couldn’t lift my eyes to his, I felt his gaze upon me. He certainly sounded pleased, but what, when he saw me now, did he actually see?