Behind the counter I work fast, collecting and returning cash, making the coffee quick and right. But when collective motion suddenly stalls on the shoulders of a single customer deliberating on a cake, bovine with indecision as a queue builds up all the way to the door, I can feel the tension bubbling in me. I start doing this little thing with my fingers, rubbing the tips of them back and forth very quickly. The thing is, though, you have to stay civilised here. You have to press the anger down and keep a tight lid on it.

I’m the coffee expert at our place, the resident caffeinated snob. I grew up in tea country, the Belfast brew made hot and strong, always ready to soothe a place that lived on its nerves. You could have a coffee, sure – an instant one, usually, insipid and faintly bitter – but it wasn’t the national medicine that tea was. Coffee gave you the jitters, and we already had jitters coming out our ears. We medicated ourselves, swinging relentlessly between alcohol and tannin.

Now, in London, I like coffee even more than tea: I seek out the jitters, packaged into strong little bursts throughout the day. Short, sharp shots. I know about the countries it comes from, the beans, the roast, the grinding process; enough, at least, to satisfy anyone who wants to have that conversation at length, and it seems quite a lot of people do. Customers want to be subtly flattered on their discernment. I buy therefore I am. From their footwear to their lunchtime sandwich, they are the sum of their choices. Who am I to sneer at that? It’s what they have left, now that for so many of them God’s a busted flush and a family is either falling apart or yet to be acquired.

I can play that game if they need me to. From the way I talk – fluent and considered – I can seem to care more about it than I really do. That’s not to say I don’t care at all.

Still, something’s changing here. I can feel it in the air, even while I open the curtains and bat the thought away each morning. The beast that circles the shadow of the campfire is dragging closer. I know its smell. When I first moved to London I felt lighter, carefree. Just then, it was a place that was gradually getting clean of fear, not counting the restless electricity that haunts any city, that stirs and flashes in gang fights and criminality. But the old IRA terror, the fractious marriage of nationalism and Marxism, was fading away.