Some houses keep memories. Others keep secrets.

The portrait comes up in a mixed sale in Naples, catalogued as anonymous, and nobody has looked at it properly in eighty years. Elena Ward looks at it properly. That is her whole job and most of her personality — and what she finds on the back of the canvas is half a torn label, a family name, and the beginning of the words the house on the cliff.

Nine days is all she can get. She spends them in a village on the Amalfi coast where nobody will talk about the family in the big house, in a building that is not ruined but unfinished, sorting through eighty years of paper that nobody has ever thrown away.

Adriano Ferretti inherited that house two years ago and has been restoring it slowly, alone, at weekends. There are eleven rooms and he has been into eight. He is quite certain that the woman in the portrait is not in his family — he has the tree, drawn up by lawyers, and there is no such name on it.

But there is a gap on the tree the width of a person. There is a household ledger with six years of paint bought for somebody who is never named. There is a floor on the cliff edge under eleven centimetres of soil, and a doorway cut through the outside wall of a house in 1932 and sealed before somebody built two rooms around it.

And there is a man in Rome who will pay forty thousand euros to make a nine-hundred-euro painting quietly disappear.

A slow-burn romance and a quiet mystery, set on the Amalfi coast — about a woman who was removed from a family's story, the two people who put her back, and what it costs to be certain rather than comfortable.