What have I done?

the long version

"Kathryn Brooker is the headmaster's wife, while her husband spends his days conducting assemblies and disciplining unruly teenagers in the grand halls of Mountbriers Academy, Kathryn spends hers in a beautiful cottage in the manicured school grounds, baking scones for her son's cricket match and perfecting her recipe for coq au vin. From the outside it would appear that she has a perfect life, a happy family without a care in the world. But they would be wrong, Kathryn is trapped in a nightmare"--Inside front cover.