Arnold Landon can't help but feel drawn to Oldham Manor, an atmospheric medieval house in the middle of nowhere.

When he is invited to catalogue the library there, he jumps at the chance. The place is a maze of musty old papers and books.

And that's not all. Late one night, he stumbles on a secret passage, twisting deep under the ground. Where will it take him? And why was it walled up?

When a stranger turns up dead in a ditch, Landon begins to realize that someone is watching his every move. And they have a plan to ensure the past stays buried for good.

What did the victim know that was worth killing for?