Reeling from secretly observing her boyfriend cheating with a female colleague, as a distraction from the anguish she experiences, Ashley Jones visits an exhibit about American heiresses who’d married English lords. To her amazement, the curator shows her a painted subject, Lady Harriet Davenport, who could have been her 19th-century doppelganger. She studies the woman’s beautiful, hauntingly sad face and reads up on her equally sad history—of being separated from her true love in America only to end up in a loveless marriage or, rather, a marriage of convenience faraway in England.
Ashley returns to her small apartment and feels a strange connection with the woman who’d apparently died sleepwalking in a blizzard while her husband was away with his mistress. When she falls asleep on her sofa, she awakens in a four-poster bed in the presence of a chambermaid. Somehow, she has traversed the boundaries of time to enter Lady Harriet Davenport’s body. She experiences the stroppy family, discovers a hidden diary chronicling the woman’s adulteress lifestyle, and the paranoid belief someone is out to kill her.
The aloof Lord Richard Davenport is a man determined to have everything his way. When he meets the new version of his wife—an incredibly stubborn, feisty natured, argumentative, and ill-behaved woman—he tries to improve her, only for Ashley to openly resist, deliberately creating upheaval in his boring, structured life. Entries in Harriet’s diary note he only married her for the money and that he had a mistress who often came to stay with him at Evercrest Hall.
Ashley doesn’t count on falling in love with Lord Davenport, and she senses his feelings are growing for her despite what Harriet had said about his cold, unkind nature toward her in the diary. The problem is the rapidly growing bond between them triggers a chain of events detrimental to her existence as she experiences firsthand strange occurrences in the night and threats to her, Lord Davenport, and his young family’s lives.