For some reason there seem to be three different shades of the cover bouncing around, or at least that's what I found by google.
The image search also turns up
which, lamentable posture aside, looks a lot more interesting.
We start off twelve years earlier (a rather awkward way of wording it when we haven't spent any time in the "present" yet). Little Chloe is standing at the basement door. She's terrified of the basement but the babysitter is telling her to go down and help her find something.
"Did you tell Emily about the basement?"
"I most certainly did. No basements for Miss Chloe. That door stays closed." When Daddy came around the corner, Mommy said, "We really need to talk about moving, Steve."
That's interesting. It seems her mother may have some idea of what's going on. She isn't just letting Chloe avoid the basement but treating it as something serious enough to warrant moving.
Chloe doesn't want to go down, and the babysitter gets strangely nasty, first calling her a baby and then threatening to come back and lock her in the basement if she doesn't show up immediately. The threat works and Chloe bolts down the stairs.
There'd been others, before Mrs. Hobb scared them away. Like old Mrs. Miller, who'd play peek-a-boo with Chloe and call her Mary. And Mr. Drake, who'd ask weird questions, like whether anyone lived on the moon yet, and most times Chloe didn't know the answer, but he'd still smile and tell her she was a good girl.
She used to like coming downstairs and talking to the people. All she had to do was not look behind the furnace, where a man hung from the ceiling, his face all purple and puffy. He never said anything, but seeing him always made Chloe's tummy hurt.
So yeah, ghosts. I was told necromancy, though, and I feel necromancy needs a certain bit more. I will be very disappointed in everyone if she just ends up a psychopomp. Psychopomp is a really cool word and all, but I want rending the fabric of the world to her dark whims, not just consulting politely with dead people.
(This is one of those rhetorical questions. I'm already committed, if the answer is "nope, just ghosts!!!!" you are just making me disappointed faster.)
Anyway, for now, creepy ghosts will do.
Just the night lights were on, the ones Mommy had put everywhere when Chloe started saying she didn't want to go downstairs and Mommy thought she was afraid of the dark
So it seems her mother doesn't really know what's going on and is just going off Chloe's statements. That's some pretty good parenting, then. I wonder if it's a matter of her not really caring if it's true because it's obvious Chloe's scared either way or if she's the sort of person who's willing to believe in those things. The latter seems more likely, but the mother's still using the basement herself, which would suggest the former. (If I believed there were ghosts in the basement but I just couldn't see them, I would never set foot down there again.)
Chloe sees movement but it's okay, it was only the hanging man, and all she could see was his hand peeking from behind the furnace as he swayed.. So Chloe is a bit more hardened than you'd want a little kid, and also, the fact she's so calm about something like that just makes you wonder how awful the ghost she's afraid of must be.
She gets to the cold room, but the lights are off there too, but she's told to hurry up anyway. Her babysitter is being extraordinarily cruel, isn't she? Unfortunately, the next thing Chloe hears is footsteps above, but it's too soon for her mother to be back...and then her babysitter is shouting her name up on the first floor. Turns out ghosts can mimic voices.
Mrs. Hobb's skin rippled and squirmed. Then it went black and shiny, crackling like twigs in a campfire. Big chunks fell off, plopping onto the floor. Her hair sizzled and burned away. And then there was nothing left but a skull dotted with scraps of blackened flesh. The jaws opened, the teeth still glittering.
And that's our opening!
It's relatively predictable - you know going down there is going to go badly, and certainly, by the time Chloe is being talked into going into a dark room you can guess she was tricked down there. The story does a pretty good job of putting the final clues to that right near the point the ghost reveals herself, to avoid an excess of dramatic irony (sure, if you're familiar with these stories, you might guess it was a ghost all along, but hey, YA. Stuff's always new for someone). Dramatic irony can do a good job of building suspense, but it is possible to take it too far (the Bartimaeus trilogy, for particularly extreme examples).
We are not really looking at the best description either - when you cook meat on a fire, how often to do big chunks plop off? Burning should have her flesh shrinking and tearing/flaking off, but those would be dry sections, while plop is a wet noise.
There's also a weird amount of product placement - the Scooby Doo heads on her slippers bobbing, the Coke's in the cold cellar, "I see you're playing with Princess—I mean, Pirate Jasmine. Has she rescued poor Aladdin from the evil genie yet?" I don't think people should have to use a generic term, but this seems a bit thick for how short the opening is. It seems like it's being done to establish verisimilitude and how this is EXACTLY LIKE OUR WORLD IT COULD HAPPEN HERE, but perhaps because of how often I see it used like that it has the opposite effect on me these days.
Let's look at what we know so far about how the world functions:
Apparently, Chloe's ghost sensing is either unique or at least not known enough for her parents to understand quite what's going on.
It does not appear ghosts can physically interact with the world, although it may just be that Mrs. Hobb didn't choose to do that while luring her in. It seems unlikely - if ghosts can move things, then it's pretty easy to prove they exist.
They have a limited mobility. None of them came out of the basement and Hobb is certainly motivated to do so. On the other hand, Chloe says Hobb arrived more recently and also drove out the other ghosts. So either there are hotspots that allow any ghost to exist within a certain range and they can travel between those, or ghosts have a large enough range that they can move to a different section of it. It could also be an earth thing, where they can go anywhere below a certain height, or ghosts might be able to redefine their range slowly, over time. (I've never seen that last one but it sounds cool. It'd fit well with how haunted house stories sometimes go, where at first the manifestations are limited to a particular location and then slowly expand to encompass the whole place.) I'm going to guess the hot spot option or anything else that would allow ghosts to get around freely doesn't apply, because otherwise it raises the question of why the nicer ones never came back with friends to drive Hobb out again.
It could also just be that ghosts have an active and passive form, and she harassed them into not manifesting. That's more boring, and wouldn't quite address why she wasn't around originally, unless ghosts normally spend a large portion of their time inactive and unaware of their surroundings and it took some time for her to notice Chloe.
Ghosts can look normal or scary, presumably the way it looked when they died. It isn't clear if they can change their form beyond that. Hobbs sounded very convincing as the babysitter, but that could have just been acting, so it's not clear if that's actually a legit power they have either.