This was a pretty dismal mystery, and I have zero interest in reading additional titles in the series.
It's a weird mix of gothic mystery and heavy-handed humor, but it just isn't successful. So Nanna was quirky, we get it. But her actions (specifically with cash) are pretty ridiculous. The mystery of what's "haunting" the house is odd, and there are way too many characters set forth as suspects. Overly friendly artistic neighbor who happens to have a mental illness (but it's fine as long as she stays on her medicine), another neighbor who hates cats, creepy couple next door who lurk behind trees, ex-fiancee who randomly tracks her down across the country, former friend who appears to be losing her grip on reality... All these cliche, overdone people were just too much - the story would have been so much better if there were just 2 or 3 "suspects" who were well developed.
And the romance? Again, hard to believe as it's so rushed and full of cliches.
I actually found myself rolling my eyes at the ending (trying not to spoil it). One phone call and it's over, just like that? How was the "treasure" known about anyway? Again, rushed and no good explanation, so no satisfactory moment as you see the mystery closed.