She’s finding it hard to concentrate, though. It’s been like this since she returned from London – memories competing for attention, intrusive thoughts and suppositions. She sighs, twiddles her pencil, fiddles with the mess of papers on her desk: receipts, invoices, notes.

Grabbing a piece of honey cake from a plate, she crams it into her mouth. Sticky and sweet, it’s the only food she has eaten all day. Last week, Agata sent her home with a Tupperware box full of cakes and pastries, recipes passed down through generations. Marina wonders what kind of cook her own mother would have been.

Throwing down her pencil, she strides to the window. Snow has given way to rain, and the sky is overcast, smeared with grey. Without any morning sunshine, the fields are dulled to yellow, and the trees and hedgerows seem more black than green. Beyond the church spire on the hill is the Westbury White Horse. It is mythical and magical. Marina imagines the horse taking off and galloping across the plain.

Ruth had told Marina from the beginning how she and David had come to adopt her. That Marina had been abandoned, left in the hallway of a shared house, dressed in a gown and a neatly pinned nappy, wrapped in a shawl of the deepest blue. Ruth said her birth mother must have loved her very much because she had put her somewhere safe where she would be found.

The media had run the story, nicknaming her Baby Blue. It was a Spanish nurse who had called her Marina, which came from the Latin and meant ‘of the sea’: with the blue shawl and her dark looks, it seemed to fit. David and Ruth had agreed. Naturally, they’d added their stamp, naming her Marina Zoe Alexander – Zoe for ‘life’.

Marina had listened to these stories of her birth with her knees drawn up and her face serious. She had stored away the details and conjured an image of the woman who was her mother, imagining her with thick, dark hair like her own and dark eyes too. A tragic figure always intending to return.

Ruth had saved dozens of newspaper articles and had kept them in a box in her wardrobe. Marina liked to sneak into her bedroom and study the photos of the house, which seemed like a mansion compared to the cottage they lived in.

When she was older, Marina had read the articles more closely. She had made notes, gathering information about the tenants mentioned and making a plan of who had lived where in the house. A pregnant woman had been spotted nearby. Could that have been her mother? Where had she gone? Marina had searched newspaper archives for unexplained deaths, but there were no dead young women reported, only the corpse of a man who had been dragged from the lake on Tooting Common.