It is Halloween night, and the local museum in King's Lynn is preparing for an unusual event - the opening of a coffin containing the bones of a medieval bishop. But when Ruth Galloway arrives to supervise, she finds the museum's curator lying dead beside the coffin. It is only a matter of time before she and DI Nelson cross paths once more, as he is called in to investigate. Soon the museum's wealthy owner lies dead in his stables, too. These two deaths could be from natural causes - but Nelson isn't convinced.