Coming back for more

“I haven't given blood for 18 years. First there were babies, then work, and then I was drunk.” Caitlin Moran on being a donor again.

All church halls smell the same - a combination of hot dust, floor polish and tea.

All church halls sound the same, whether they're holding a jumble sale or collecting votes on polling day: a polite British murmur, occasionally punctured by a baby yelling and the sound of the pensionable samovar clanking into action.

But today, the church hall looks different. There are two huge blood-donation vans in the car park and, inside, a bustle of nurses in blue tabards, servicing 12 reclining chairs where people lie, giving blood.

Outside, it's beautiful: swifts dolphin-scream as they chase insects; horse chestnuts are in full bloom. But in here, people have given up picnics, walks, lunch hours and housework to give a pint of blood, to be kept in plastic bags, carefully labelled and stored in refrigerated units until needed.

One man has brought his toddler; with one hand he keeps a bottle jammed in her mouth, while the other arm is tethered by a needle. Another man, in a suit, turns up. He looks as if he spends most of his day shouting at people on the phone, making big things happen. Today, however, he sits patiently on a chair, waiting. He is greeted as a regular.

“To donate feels like an act of thankfulness”

I haven't given blood for - God, 18 years. First there were babies, then work, and then I was drunk. I know why I want to give blood: I have no religion, but to donate feels like an act of thankfulness. It is fascinating, to be this useful.

I am taken into a booth by a nurse, who does a finger-prick and drops a bead of blood into copper sulphate.

"Iron test," she says. The bead sinks. My blood is heavy with iron. How amazing to be full of metal. To see it.

On the reclining chair, the needle is bigger than I remember it - hollow, like a tunnel being pushed into a ring road of arteries and veins. I make myself watch, because this is interesting, too. It hurts as much as pulling out a single eyebrow hair. I look around at everyone else - all calmly lying back as they donate, as Tony Hancock put it, very nearly an armful.

I'm surprised when I start to cry.

It's because, in the past few years, we have been led to believe that we are a bit harried, a bit unyielding - that the world is going to hell in a handbasket, and the smart thing to do is to harden your heart and look out for yourself. We've split into camps, tribes.

To begin to talk is to fall into an argument, and reveal yourself as someone else's problem or enemy. Baby Boomers are pitted against Millennials, Leavers against Remainers - and yet, even in our furiously bonded groups, we've never felt more anxious or alone. Along with sparrows, bees and skylarks, it feels as if love is in decline, too. You do not see it around so much any more. You do not open the door and hear it singing.

But here, this room is full of the least talked about love - love for someone you've never met. Here is a system set up, without profit or material reward, based on a simple idea: of a country never wanting to see someone bleed out on a table when there were a thousand people out there who would have given their blood in a literal heartbeat if they'd been asked.

“You will be the magic that stops a life from being undone”

This is where you are asked. This is where you can lie on the bed and scrunch your hand into a fist, over and over, sending all the luck in the world to the team who will, one day - one terrible, unlucky, critical day for someone - break open the seal on your bag and try to keep someone alive.

Maybe this heartbeat will turn someone's lips from blue to pink again; bring back a mother or a father or a child. All the calmness and love in this room is being sent into some furious, terrified future in A&E that you will never know about, but you will be the magic that stops a life from being undone. Perhaps the life of someone you know. Perhaps your own. Perhaps you are not donating at all, but lending. As others once, maybe, lent to you.

The church hall, the vans, the nurses, the donors, the samovar clanking - Britain thinks it is having an identity crisis, but a country is, simply, what it does, and it does this. In church halls, like this, smelling of hot dust and love.