Manhattan Grimoire by Sandy DeLuca

A crippling blizzard, grisly discoveries in an old church in Harlem, a small apartment building cut off by the mounting storm, its tenants trapped with a vicious killer that may or may not be human, and an unholy manuscript stolen from a dead sorcerer that could very well hold the secrets to opening the gates of Hell.
Gina has seen strange visions since childhood. Her mother was considered insane for having the same affliction, and before her disappearance, Gina's sister Allie was obsessed with black magic and "saw" things too. It eventually led her to a depraved conjurer known as Mojo DeCanne, a man who possessed a book of demonic spells Allie stole and hid in Gina's apartment in the days before she vanished. Now, as Manhattan braces for the worst snowstorm in decades, and Gina's visions become worse, blurring the lines between nightmare and reality, Mojo DeCanne has come looking for what is his. In order to solve the mystery of her sister's disappearance and the meaning behind her own shattered life, Gina must first survive the night and somehow stop an unimaginable evil from fulfilling its horrific destiny. Darkness falls on Manhattan. The blizzard grows worse. And the lights go out. From Goodreads

I was not convinced by the horror in this book. The end hints that everything had just been going on in the main character's Gina's mind because of some hallucinogenic narcotics even as she still believes everything.

This book qualifies for:
Goodreads 2013 Reading Challenge
Tower Teams Read 2013-2
Serious Readers 2013
2013 Ebook Challenge
2013 Women Challenge
Quick fix Challenge 2013 (180 pages)
2013 Literary Exploration Reading Challenge
Spring into Horror 2013
2013 Why Buy the Cow? Reading Challenge (free on Amazon.uk 8th of January 2013)
Let Me Count the Ways Reading Challenge 2013 (180 pages)