Hell's Hammer - Haunted Village Series, #2

An experiment in terror pushed him to his limits. Now Subject B is fighting backHis name is Marcus Holt. He is a fighter, a survivor, and a decorated combat veteran. But to the sadistic Professor Abel Worthe, Marcus is known merely as Subject B -- a pawn in the scientist's inhumane experiments. Worthe is an expert in the study of death and fear. And he intends to push Marcus to the limits of human endurance.
Trapped in the shadowy streets of a haunted village, Marcus and his young friend Alex must deal with a new threat: the ghost of a vicious murderer, who kills with a bloody mason's hammer. Their task is made even harder when two new subjects, a bickering couple, are added to their group, drawing the wrathful spirit right to them. As Marcus and the others struggle against this supernatural horror, Professor Worthe observes the psychological effects of their extreme terror.
But Marcus Holt is a soldier. And he's not going down without a fight. Professor Worthe is about to learn that a caged animal is the most dangerous subject of all.