Monica Dean thought she came into great wealth from a relative. However it was just a large home that came with a housekeeper. The house has a reputation of being haunted.
Monica planned to turn the house into a hotel with paying guests. However guests had fled in terror with a bed collapsing or clothes being shredded.
Monica things it is sabotage, the bed posts seemed to have been sawn. She has had offers for the purchase of her house. Monica thinks that on each occasion it has been the same man in disguise.
Tommy and Tuppence investigate, they reckon that her relative had once buried something valuable in the grounds. This is why the someone else wants to buy the house.
I thought this was another episode that would largely be told in flashbacks. However the second half improves as Tommy and Tuppence go to the house to investigate. Tuppence pretends to be an aristocrat who has an interest in the supernatural.
Given there are such few characters. I think you do not need to be a private detective to figure out who might be involved in the skullduggery. The episode at least gets going in the second half. There are clues to figure out, there is even some peril and Albert has something to do as well.
Pam St Clement makes an early appearance as the housekeeper.