Poltergeist by Kat Richardson

Harper Blaine is a greywalker, someone who can see into the grey realm that is death, and either talk to and interact with the ghosts and spirits who make it their home, or even enter it as well.

After having dealt with Vampires and vengeful spirits and necromany is her last novel, Harper is hired by a Professor named Tuckman who wants her to look into an experiment he's been performing with a group of volunteers. The volunteers are trying to make a fake spirit, or poltergeist which can affect things in the real world. And in this manner, they have had some success.

He's led them to believe that they can actually do this thing, that they have the power and the will to make such an entity manifest. They even came up with a name for the poltergeist/spirit (Celia), and one of them even painted a picture of "her" for everyone to focus on. And now, just such a spirit has manifested, letting itself be known by way of knocks and various other manifestations.

But the problem now is that the experiment has been, if anything, too successful. Though Dr. Gartner Tuckman put a ringer into the group who could control a variety of effects that would make them think they had been able to make such an entity, it has gotten far out of control, and the participants, and entity, have shown behavior that almost certainly can't be possible.

The professor wants to know if someone is tricking him and the rest of the experimental group. And if they are, how it is being done, for with all his own trickery, he can't figure out who is causing these incidents, or how. Harper, who can hear and see into the Grey, wonders if there is possibility that the men and women in the study could have raised an actual ghost. But when Tuckman's inside mole is slain, Harper begins to feel that something is wrong- very, very wrong.

Though she never met Tuckman's henchman in person, it turns out that Mark Lupoldi worked at her favorite store. She knew him, and liked him, simply as "Mark". And it appears he had an argument with someone in the store just the night before he died. And on top of that, one of the gargoyle statues in the store nearly hit him in the head... without anyone touching it, a sure sign of Poltergeist-like activity.

The rest of the participants are also getting nervous, for "Celia" is getting ruder, and nastier, from pinches and pokes to stealing items and throwing them at the others, it's obvious that the study has gone far out of Tuckman's control. But at the same time, he doesn't want to stop. It's as if he wants to push these people to see how far he can make them go.

And that's a problem, because it seems that one of those people is psychopath who has taken control of the entity named "Celia" and may have used it to murder Mark... and may now have the intention to murder others. And worse than that, the entity definitely exists in the Grey, and it seems to be getting stronger, or at least, angrier. Can Harper fight off this man-made spirit that has taken on a life of its own? And how exactly can she do that? If she can't figure it out, she may end up in the Grey forever...

This book is a sequel to "Greywalker", and I loved it just as much as the first. A lot of characters from the first book reappear here, not the least of which is Chaos, Harper's ferret, Quinton, her tech-fixer guy, Mara and Ben, the married professors- one of whom is a witch and the other a philosopher, their sproglet Peter, and the vampires Cam and Carlos. It was nice to see all the usual suspects back for another round, as well as Will, Harper's love interest, who only speaks with her on the phone, being in London.

Harper may be comfortable with her sight into the Grey, but she's by no means familliar with her abilities. Yes, she's working to improve that, but she's walking blind into her abilities with the Grey. No one else can really guide her, as no one else can see exactly as she sees or what she sees, not even former black magician Carlos or Ben and Mara. They can try, but for Harper, learning about the Grey is like groping in a dark room. Only she can do it, and learn (slowly) from what she does. And in the end, she's going to have to pull her own fat out of the fire, even if she needs a little help getting there.

I find the Grey to be utterly fascinating, as are Harper's adventures in it. Each story is a learning experience both for Harper and the reader, and we grow with her, groping towards internalizing what we see and learn from her explorations into this shadowy realm. I really enjoyed the book and look forward to reading the next two in the series, the latest of which has just come out. This is a great series, and if you like gritty, urban paranormal adventure, this is the series, and the book, for you. Highly recommended.