The assignment: Craft a novel from the literary equivalent of found objects. Consider the narrative possibilities contained not just in letters and e-mails, but in school report cards, emergency room bills and police reports filed by night managers at Westin Hotels.

A photograph on the pamphlet extolling the benefits of emigration features women in red swimsuits, skidding on water skis across Sydney Harbor — a jarring contrast to the bleak circumstances of a British couple named Charlotte and Henry in their mold-afflicted, too-small house in Cambridge.

The opening scene is perfection. We meet the eponymous heroine of Diane Johnson’s latest novel, “Lorna Mott Comes Home,” as she rides in the back of a taxi, en route to the train station in Lyon.