In the Midnight Hour — Cate Masters

Buried things have a bad habit of resurfacing, often when Josie least wants to deal with them. Nothing like a dead person to lend perspective to her miserable life.
When she signs on as a ghost tour guide in Gettysburg, Josie gets a fresh glimpse at the spirit world. Civil War soldier Nicholas Whitby is more real, and more attentive, than any living guy she knows.
Until Garrett joins the tour company. He warns her against Nick, who plans to destroy The Gate between worlds on Halloween.
Josie's torn between the sweet Nick she knows, and the fear growing with each nasty encounter with Gettysburg's ghosts. Just when she's finally learned to feel comfortable in her tattooed skin, she must divine the truth. Will trusting a dead man unleash a legion of vicious spirits upon the earth?
Trick or treat never held such deadly consequences. Will Gettysburg become a ghost town for real?