Jo Currington

After getting wounded in the trenches, Harry finds himself recuperating at Stowe House, a country house in the folds of the South Downs near Chichester which specialises in shell shock cases for the lower ranks. The condition is poorly understood at the time and there is local opposition to the presence of the patients. Their behaviour and treatment lends the house an odd atmosphere. It is surrounded by four thousand acres of woodland which Lady Stowe no longer has the resources to manage, and which now are used by other parties.
She is also getting threatening and abusive letters. Lord Stowe is absent, although he has a munitions factory in Portsmouth where there have been strikes about working conditions. As Harry's condition improves, he is taken on by Lady Stowe to try and restore some order to the estate. The psych doctor confides in him that he feels that too many patients are dying at the hospital. There had been a spate of suicides over the winter months.
But then there are a series of deadly incidents which are staged to resemble common types of death in the trenches. There is also a worrying buildup of deserters lead by the psych doctor's brother, who has had an affair with Lady Stowe, and has been waiting for her in the chalk caves in the woods all winter. Some explosives are stolen from Lord Stowe's factory, and a new doctor arrives, with a brutal new method of dealing with these patients.
Military Foot Police are deployed to try and protect the house from the attack which Lady Stowe is getting warning of. And then it all kicks off.