What it became, in its final iteration, is a wonderfully subtle story in which the experience of migrant children is filtered through the delicate, funny, effortlessly poetic account of a family’s road trip from New York to the Mexican border, in which the central couple’s marriage disintegrates even as they strive to document the disintegration around them. Lost Children Archive, longlisted for the Women’s prize for fiction this week, started out as an angry screed, overly didactic and too bogged down in politics. The act of bearing witness would, ultimately, become the driving force behind the novel to which she returned. They chase after life, even if that chase might end up killing them.” If and when they finally reach the US, they fall into the hands of immigration officers known to shout: “Speak English! Now you’re in America!”, and a new nightmare begins. “Go in alive, come out a mummy.” But of course, “children do what their stomachs tell them to do. “There is a saying about La Bestia,” writes Luiselli. Those who don’t fall on to the tracks risk death from exposure, overhanging branches, or rape and violence from smugglers, thieves and police who attack people onboard. What she was seeing was this: traumatised children who had entered the country, unaccompanied, aboard La Bestia – “the beast” – a network of freight trains on the roofs of which half a million Central Americans ride annually. That book was personal testimony to what I was seeing.” “I couldn’t think or write about anything else.

Luiselli’s writing stalled and in a fever she wrote Tell Me How It Ends, a non-fiction account of the terrible plight of these children.

It was heartbreaking and hard, and none of those she helped to find pro bono lawyers has, in the years since, been given permanent leave to stay. For months, Luiselli, who was born in Mexico and lives in the United States, had been volunteering as an interpreter for undocumented child migrants appealing for asylum in the US.

A few years after Valeria Luiselli began writing Lost Children Archive, her third novel and the first she has written in English, she broke off to write something more urgent.

Tell Me How It Ends by Valeria Luiselli