The Valley of Secrets by Charmian Hussey
"Stephen Lansbury is an orphan. He thinks he has no relatives at all -- until the day a letter arrives telling him that a distant uncle is dead. Suddenly Stephen finds himself the only heir to a great estate in the countryside. So Stephen sets off to claim his inheritance . . . but when he arrives, there is nothing to greet him at Lansbury Hall but a mystery.
The puzzle is as tangled as the vines on the hall's front gate, but two things are clear: Stephen's uncle kept to himself, and none of the townspeople knows he's dead. But why does Stephen feel that something or someone is in the house?
To escape the slightly creepy feeling that someone is lurking, Stephen starts to read his great-uncle's diary. And a fantastic truth unfolds. Soon Stephen is sure: While the mystery of Lansbury Hall is stranger than he could have imagined, it's not nearly as incredible as reality. . . ."
Softcover, minor wear from use, binding tight, pages bright, a nice copy