Zara opens her notebook at a fresh double page and stares at the dog-eared charts on the wall. Her classmates do the same, roughly speaking, each pondering in their individual way the challenge Mr Garver has set. One chews a pencil, a second scrutinises the gas mask by his desk, fellow scholars steal anxious glances or cast their eyes blankly heavenward. Zara flips a plait back over her shoulder and copies the date from the blackboard, recollecting the days when, for exactness, she had been given to add ‘20th Century Anno Domini’. She smiles and reaches for her wooden measure. Keeping space for the heading, she marks out a long-shafted arrow to stand as a margin, etching a notch by every second line.

Zara starts by printing the year 1900 to the left of the arrow, and notes to the right that her father was born then; she places 1908, for her mother, above the first notch. The dates carved on the local memorial are followed by her own birth in 1930, her sister’s arrival, the outbreak of the present conflict, the day she packed her suitcase for the journey from London. She schedules the end of the war three years hence, for it must surely last no longer than the first.

It occurs to Zara that whatever she writes now she can simply make up for herself. She anticipates that children will soon become kinder to each other, forecasts the discoveries that she imagines being made and completes the column by inscribing the impossibly distant ‘2000’ at the foot of the timeline, beside her shaded arrowhead. Mindful of Mr Garver’s talk that very morning, Zara predicts next to it, ‘People have stopped using words that make trouble in the world’. She hopes that will not be the work of an entire century, but deems it a fitting way to round off the piece.

How much of this would come true, though? It was one thing to picture the future, after all. Hundreds of teachers must have asked thousands of children to do that over the years. Yet here they were. Mr Garver had described this as the most terrible of wars. She will add paragraphs to the page opposite, she decides, and set each alongside the events to which it belongs. That way, she can breathe life into the story, and tell of the part she might play, starting here, right now, in the village she is beginning to call home.

Zara stops, catching sight of the gap she has left at the top. Casting around, her eyes alight on a faded poster, One Hundred Years of the Railways. She allows her fingers to tap, tap, tap on the desk. She’s laid down a hundred years herself. One hundred years of… She takes in the date, alive to the way she would once have extended it. The title comes to her, and she picks up the pencil again.