Imagine that you are ten years old, and it is the first morning of September.
You are standing in the school playground, but there is no lesson today. You are wearing your coat, even though the morning is warm. Tied to a buttonhole is a luggage label, the brown paper kind people tie to a suitcase. Somebody has written your name on it, and your age, and the name of your school, and the address of your house.
Over your shoulder hangs a small square cardboard box on a piece of string. Inside the box is a gas mask.
In your other hand is a bag. The letter from school said what to bring: a toothbrush, a comb, a handkerchief, a change of underclothes, something to sleep in, and plimsolls if you owned any. Some children had a proper suitcase. A great many carried a pillowcase with everything bundled up inside it.
You do not know where you are going. Your teacher does not know either. Neither does your mother, who is standing at the school gate, because mothers had been asked not to come to the station.
In three days, this happened to about one and a half million people in Britain. Most of them were children.
The government gave the plan a name. They called it Operation Pied Piper.
The Pied Piper is a very old story from the town of Hamelin. A man in bright patched clothes offered to rid the town of its rats, and he did it by playing a pipe, and the rats followed the music into the river. Then the town refused to pay him. So he played his pipe again, and this time it was the children who followed him, out of the town gate and up into the hills, and they were never seen again.
It is a strange story to name a rescue after. Somebody in a government office had pictured the piper walking away with a long line of children behind him, and that was the part they meant. Nobody seems to have thought very hard about how the story ends.
The reason for the plan was aeroplanes. All through the nineteen thirties, people had believed that the next war would begin with bombers, that they would arrive on the very first night, and that the cities would burn. There was a phrase everyone repeated: the bomber will always get through.
So the plan was to empty the cities of children before the bombing started. The evacuation began on the first of September, nineteen thirty nine. Britain had not even declared war yet. That came two days later.
The children assembled at their own schools, as if it were an ordinary morning, and then they walked to the railway station in a long double line. Teachers called it a crocodile.
Some of them sang. Some of the smaller ones thought they were going on a school trip, because nobody had explained it in a way that made sense. Older brothers and sisters had been told one thing above everything else: hold onto the little one, and do not let go.
At the station the platforms were packed. Teachers moved along the lines with clipboards, reading out names. There were no announcements about where the trains were going, because nobody was allowed to say. Some children had never been on a train in their lives.
The journeys were long and slow, and they often went the wrong way round to keep the main lines clear. Children who had eaten their entire packed lunch in the first half hour spent the rest of the day hungry. Some were sick. Some slept.
And at the school gates, a long way behind them now, the mothers had been asked to stay away, and many of them had come anyway, and stood at the end of the street to watch the crocodile turn the corner.
At the other end there was usually a village hall.
The children were walked in from the station, tired, holding their labels and their gas mask boxes, and they were lined up along the wall. Then the local families came in to choose.
This is the part that survivors remembered for the rest of their lives, and it was almost never the train they talked about. It was the hall.
Strong looking boys went quickly, because a farm could use another pair of hands. Small tidy girls went quickly too. Brothers and sisters were split up all the time, because a family would say, quite reasonably, that they only had the one spare bed. The billeting officer wrote names in a book.
And at the end of the afternoon there were always a few children left, sitting on the floor with their bags, while the officer walked around the village knocking on doors.
What happened next was that two halves of the same country met each other, and neither one could quite believe the other was real.
City children saw their first cow, their first field of wheat, their first hedge. They discovered that the countryside at night is properly dark, with no street lamps at all, and that it is not silent, because things move about in it.
The village families got a shock of their own. Some of the children who arrived had no shoes. Some had never slept in a bed by themselves, because at home the whole family shared. Some had never used a knife and fork, and some had never had a hot bath, and one or two had never seen an egg that was not powdered.
The children were surprised right back. Plenty of cottages had no electric light and no tap indoors and no lavatory except the one at the bottom of the garden. In the city you went to bed when you were told. Out here you went to bed when it got dark.
Some of it went beautifully. There were children who ate properly for the first time in their lives, who learned to swim and to ride a bicycle and to name birds, and who wrote letters to the family that took them in for the next fifty years.
And some of it went badly. There were children who were treated as free labour, or who were made to feel like a nuisance every single day, and who counted the weeks until they could go home.
Both of those things are true at once, and the story is not tidy.
Then came the strangest part. The bombers did not arrive.
Autumn passed. Winter came. In the cities the sandbags sat by the doors and the barrage balloons floated overhead and nothing at all happened. People started calling it the Phoney War.
So the children began to go home. By January, roughly six out of every ten evacuated children were back in the cities with their families, and quite a few parents said they were never sending them away again.
In September of the following year, the bombing began for real. It went on, night after night, for months. The trains filled up all over again.
Some children were evacuated three or four times over the course of the war. Some stayed in the countryside for five years, and came home to a mother whose face they had trouble recognising. And some came home to a street that was not there any more.
The luggage label was real, and a surprising number of evacuees kept theirs for the rest of their lives. You can see them in museums, brown and soft at the edges, with a child's name in an adult's handwriting.
The gas masks were real too, and the small children had special ones. An ordinary gas mask is black, with a snout, and it terrifies a four year old. So the government made a version in red and bright blue with big round eye pieces, and everyone immediately called it the Mickey Mouse mask. It was designed to look like a face instead of a monster. Gas was never used on British cities, and the masks were never needed.
Here is a question worth holding onto. The whole plan was built around the children, and it was argued about in parliament and in the newspapers for years beforehand, and not one single person asked the children what they thought about it. It simply did not occur to anybody. That is worth remembering the next time an adult decides something enormous on your behalf.
And here is something to think about tonight. If you had to fit everything you would need, for a number of months that nobody would tell you, into one pillowcase, what would you put in it? And harder than that: what would you have to leave on the bed?