The year is 1856, and orphan Abigail Tamper lives below stairs in Greave Hall, a crumbling manor house in London. Lord Greave is plagued by madness, and with his son Samuel away fighting in the Crimea, the running of Greave Hall is left to Mrs Cotton, the tyrannical housekeeper. The only solace for the beleaguered staff is to frighten Mrs Cotton by pretending the house is haunted.

So when a real ghost makes an appearance - that of her beloved mother - no one is more surprised than Abi. But the spirit has a revelation that threatens to destroy Abi’s already fragile existence: she was murdered, and by someone under their very own roof. With Samuel returned to England badly wounded, it’s up to Abi to nurse him back to health, while trying to discover the identity of the killer in their midst. As the chilling truth dawns, Abi’s world is turned upside down.