Think back over the two visits. The officers climb ladders and chase across roof tiles, only to be set gently outside their own case. The teacher offers numbers and letters, and receives nonsense, a floor-sized horse — and, at last, an honest apology from a girl who never knew the rules. Both times the town’s system arrives certain, and leaves smiling and empty-handed.

A hundred years ago, most countries in Europe passed laws making school compulsory — every child had to attend, whether their family was rich or poor. Sweden was among the earliest: from 1842, each parish had to open a school, and by the 1940s a Swedish child spent seven years at a desk learning reading, writing, and arithmetic. The law had a serious purpose. Before compulsory school, many children worked instead of learning, and whether you could read depended on luck. School laws also gave towns a new duty: finding the children who did not come. Teachers kept careful attendance lists, and a missing pupil meant a visit — sometimes from the police — to make sure the child was safe and cared for. That is why a girl living alone, with no school and no parents, would draw the town’s worried attention at once. The system could be stiff, but its heart was simple: no child should be forgotten.

No right or wrong — close the screen and tell someone nearby what happened in this part. Can’t find anyone? Tell yourself out loud. The moment you teach it, you truly understand it.