The Chronicles of the Deadly Dead
14-year-old Zack Thornwood's life is turned upside down one day after baseball practice when he spots an 8-fingered man with a hole in his head disappear into the ground. Hole-in-Head Man is quickly followed by Xander Moon, a self-titled 'Hunter of the Dead' who explains that there are tons of dead people walking around pretending not to be dead. They look alive, they act alive, but they are most definitely not alive, and this is most definitely not a good thing.
Xander gives Zack the ability to tell the dead from the living through their unique odor (he smells dead people) and the two follow Hole-in-Head Man (whose name is Gus) into an ancient tomb hidden underground in the middle of suburbia. There they beat Gus to the prize contained within--a squishy spleen. The spleen is one of the legendary 14 Pieces that, when assembled, create The Osiris Machine which will bring about the end of the world.
Zack tries to go back to his normal life, but when Gus tries to kill him in the middle of a playground, he discovers the Deadly Dead are not through with him just yet. When Zack touched the squishy spleen, the location of the next Piece of the Osiris Machine was more or less downloaded into his brain. Gus and the people he works for, including the mysterious and utterly evil Miss Bubbles, want that information, and they will stop at nothing to get it.