Jonah and Joe are best friends. One terrible day, on the way to school, impulsive Jonah starts running after a fire engine - hoping to find the fire and a bit of excitement. Jonah runs and runs - and disappears, never to be seen again. A mystery and a loss that will always haunt Joe, who never stops believing that this friend could, must, still be alive and that one day he will find him.

A year, two years, three years pass and Joe still takes solitary bike rides into the countryside, one day meeting an attractive woman named Anna, who valiantly maintains her smallholding all alone. But Anna also lives with sadness - the death of her baby son, buried in the local churchyard. As their friendship grows, Joe finds an old, weathered, half-buried backpack - Jonah's backpack - on Anna's land. Now his life is in danger as he realizes that Anna has a terrible and terrifying secret . . .