Claire Rayner 
House on the Fen 

No one had seen her leave. Numbed by the inexplicable events of the evening, Harriet Darnell found herself running down the dark path away from the bleak mansion she hated, away from the cruel husband she feared. There was no time to question, no time to plan. She was free for the first time in her life, free perhaps for ever…Soon she was away from the house, away from the town, on a train bound for London. But no one — not her husband, nor the townspeople, nor even the conductor who collected train tickets — no one had seen her leave…