I picked up this book because the reviews were great and it sounded intriguingly quirky. I was very disappointed for reasons that I see echoed in a few other reviews.
The characters were pretty much only their quirks. I felt there was very little character development beyond the brief descriptions given at the beginning of the book.
The repetition of phrases drove me to distraction. For example, first Stuart tells us that Mrs. Jones "never entered [the room at the top of the Salt Tower] because the chalk graffiti left on the walls by the German U-boat men imprisoned during the Second World War gave her the creeps." Less than 100 pages later, she repeats that it is "the room his wife never entered, as the chalk graffiti left on the walls by the German U-boat men imprisoned during the war gave her the creeps." No less than three times, the same character is described as wearing "shoes that forced her toes into two red triangles." Lazy writing? Lazy editing? Both? Either way, it was extremely distracting.
The reason I kept reading was to find out the big secret. I was very, very disappointed by the anticlimactic reveal at the end of the book. Seriously, the big secret was stupid and made me think even less of the characters than I already had.
Most people who have reviewed this book seem to love it, but I wouldn't personally recommend it.