March 1891. The worst blizzard in living memory buries a train in a Cornish cutting. A young schoolmistress takes the guard's lamp and walks the line to the signal box to fetch help for a sick child. She knocks. Nobody opens the door.
March 2026. Kerra Nance runs safety for the night crew working in the same cutting. She is grieving, exhausted, and done with family. But the box is due to be lifted by crane in a few weeks, someone with a lantern keeps walking towards it, and an old woman in the crossing cottage has kept a promise for fifty-four years.
