I'm calling the podcaster / historian bloke as the murderer.
The woman in the holiday cottage was a child under the social worker who died. And came to the area to talk to her about her past.
The son is a badun. Although it just looks like he's flirting.
The storm all those years ago will be at the bottom of it
The dead woman will have had a terminal illness which is why she was tidying up her affairs.
Why Ellie haddingtons character set fire to the chair/ house I've no clue!
Next body will be the informer from the start.
Im being strong and will not binge!!!!