Jeff Sexton
Sold Short Sychological Sequel. (Yes, the alliteration didn't work with "psychological", so I had to misspell it. :D) This is one of those sequels where you actually really need to read its prior book, in this case The Retreat, first. But since both are actually perfect for when you want a spooky read (such as during Halloween, when this book releases)... that is actually a great thing in this case.
This one is perhaps a bit less gothic, though it certainly has the creepy old mansion. It also has an even deeper tangle of secrets, as characters from the first book come back to play roles in this book as well - though certainly not all of them, and even in nearly every horror tale out there, at least one person survives. So the prior bit isn't really a spoiler of anything. :D But *does* point to *why* you need to read The Retreat first.
In both cases though, you get quite a bit of tale packed into relatively short (here, 260 ish pages) books - making them a bigger bang for your buck than longer, slower tales. And making them overall better for when life is busy and/ or you are doing other things, but also want to read some books.
And as explosive as the ending was in The Retreat... here, while the explosions are of a different type... they may be even bigger and more devastating...
Very much recommended.