Agness Trevelyan witnesses an attempt on the life of Queen Victoria. The queen survived, the attacker died on the spot, but Agness, thanks to his supernatural gift, manages to notice: the failed killer was ruled by a ghost in monastic vestments! Only Pastor James Linden, Agness's guardian, has enough skills to hunt the undead, but they do not even suspect what terrible force opposes them. The investigation leads to Bedlam, the famous hospital for the mentally ill, then to the Prime Minister's chambers, then to Buckingham Palace. But what purpose is the mysterious monk really pursuing and which of the mortals voluntarily entered into a conspiracy of ghosts?..