Magpie by Piper Scott

The deaths are also Agatha Christie-like, from the nasty village squire whose head gets cut off to his bitter sister deprived of her birthright and the inquisitive housekeeper whose body is found at the foot of the stairs in the ancestral mansion The mansion is called Pye Hall, which is another Christie touch. In this collection there is a formidable array of characters, from the eccentric detective Atticus Pund and his echoes of Hercule Poirot to Susan Ryeland, a literary agent trapped in an unexpected peril in her work.