Oz Chambers lives in a haunted house. His mother wants to move, but Oz would rather do double algebra (yuck) every day for twelve months than leave. When he and his friends hear ghostly footsteps, it leads to a search for the strange artefacts that are the source of the old place’s eerie reputation. But what Oz hasn’t bargained for is that he’s not alone in that search and that solving Penwurt’s puzzles will lead to other, much darker secrets that will test his loyalty and his bravery to the limit.