The Vanishing Act of Esme Lennox
The Vanishing Act of Esme Lennox by Maggie O'Farrell, a broody mystery set in Scotland at the beginning of the last century. The protagonist searches asylum files for details on the commitment of her elderly aunt, and finds herself "reading about Jane, who had the temerity to take long, solitary walks and refuse offers of marriage." A customer recommended this to me; it was a Washington Post Book World Best Book of the Year, and I can see why.