The puzzle wood (Broché)

Miss Catherine Symonds feels apprehensive when she arrives to take up a position as a governess at remote Locksley Abbey. It's not the echoing, near-empty house with its skeleton staff that frightens her, nor the ancient woods that surround the Abbey, or even the dogs that the owner, Sir Rowland, encourages to stalk the grounds, baying for blood. It is Catherine herself who fears scrutiny : her very identity fraudulent.
She is travelling in disguise to investigate the fate of the last governess at the house, who took her own life out in the woods. For that governess was Catherine's own sister, Emily, who until now Catherine had believed to have died many years before, when they were children...