Jack Perdu lives with his father on the campus of Yale University. He is very smart and is reading a book almost all of the time. One night Jack gets hit by a car and then he starts seeing ghosts. His father sends him to a paranormal doctor in New York City. While he is waiting for his train he sees a girl named Euri. The thing that Jack doesn't know yet is that Euri is a ghost who haunts Grand Central Station. She takes him on a tour of the underground of the station, which turns out to be where the spirits of people who died in New York City go. Once Jack realizes where he is he sets out to find his mother who died 8 years ago. The thing is Jack only has 3 days to find her otherwise he will die. He and Euri follow leads and in the end find his mother, but she reveals to Jack why she can't return to the human world. Jack returns to the human world in the nick of time and tries to bring Euri back with him. When his father finds him it is just Jack and no Euri. Jack is sad that Euri didn't make it, but in some way he feels her watching over him.
A good book very similar to Elsewhere by Gabrielle Zevin. I liked the way the author used the underground to symbolize the afterlife, since most of us are buried into the ground when we die. I also liked the search for a lost soul part of the story, since most of us have either a family member or friend who has passed away, and would like to have them back in our lives even if it is only for a short period of time.