Brother Odd by Dean Koontz is based on the character Odd Thomas and his attempt to find peace in the Californian mountain monastery of St. Bartholomew's. Odd has a rather unique gift—he sees dead people—those who are unable to cross over are drawn to him in hopes that he can fix what holds them here. Some want comfort, some forgiveness and others have motives he is unable to grasp. They often complicate his life. After a tragic affair in his hometown of Pico Mundo, Odd retreats to the monastery. He is drawn to situations, and running entirely on intuition and faith that his life has purpose, he follows the pull. Odd looks outside the monastery's guest house window and sees his ghost dog Boo acting as though something terrible is in the shadows. He watches to see what has the dog's attention. Something only he and Odd can see, the other worldly, inky and sinuous shape oozes across the lawn in the shadows. Seemingly half man/half wolf, it glides without even rippling the grass it passes over. Odd wants to look away, but senses that should they ever find out he can see them, his life would become much more difficult. Only the Mother Superior (Sister Angela), Abbot Bernard, and Brother Salvatore (Brother Knuckles) are aware of his special gift. Hoping that he can help one of their own, Brother Constantine, who had been found hanged from the bell tower a year earlier, Odd is given a universal key so that no matter where Constantine appears, Odd can reach him; but life for Odd is never that simple. The appearance of a bodach tells Odd that trouble is coming as they are harbingers of chaos. The more that come, the larger the catastrophe that follows. Bodachs are drawn to pain and chaos, like moths to a flame, and while they seem unable to affect this world directly, Odd is unsure of the extent of their control.

Before he is ready to leave the monastery, Odd is instrumental in unraveling the mystery of Brother Constantine's death. The benefactor of St. Bartholomew's, John Heineman, a man Odd respects and admires, harbors a Jekyll and Hyde personality. Heineman creates a program that he believes can offer scientific proof of the existence of God. Instead he unleashes a variety of angry and violent extensions of himself and unwittingly kills a total of three of the Brothers before Odd, with a great deal of help from an NSA agent masquerading as a librarian, helps to put a stop to his manifestations. When he is finally ready to return to his home town of Pico Mundo, he says goodbye to the Brothers and Sisters, and just days before Christmas, barely down from the Sierra Nevada mountains, Odd feels the pull again. Unable to continue, he gets out and begins walking down the side of the highway following the psychic magnetism that controls his life. The surprises aren't over for Odd, though, as he finally says goodbye to the spirit of Elvis, and finds a new friend has joined him with Boo on his journey to the next adventure.