Odd Thomas is a character created by author Dean Koontz. He has a very unusual talent - he sees dead people. Many of the people he sees need him to assist with some unfinished business so that they can cross over to their final resting place. Others are just wanderers that he encounters, some malevolent, some benign.
In this installment of the series, Odd (who is named this because the "T" in "Todd" was left off of his birth certificate) is at St. Bartholomew's Monastery in the mountains of California to recover from the tragic events of the first book that took place in his home of Pico Mundo. Only three of the occupants of the monastery are aware of his abilities: the Mother Superior (Sister Angela), Abbot Bernard, and Brother Salvatore (Brother Knuckles).
The gist of this book is that while recovering, he is drawn into an investigation of the earlier death of one of the monks, Brother Constantine, who was found hanged in one of the towers the previous year. In the process of the investigation he discovers that one of the supporters of the monastery, John Heineman, has developed a program by which he hopes to scientifically prove the existence of God. However, instead of accomplishing the desired goal, the program unleashes malevolent powers that kill three of the monks before Odd can stop it.