Keepers — Gary A. Braunbeck

Everything changed for Gil Stewart on the day he saw the old man die. Gil had witnessed the bizarre accident on the highway and stopped to help. The old man couldn't be saved, but just before he died he clutched Gil's shirt and whispered a warning: "The Keepers are coming!" That was when Gil's nightmare began. At first he thought it was merely odd, a series of weird coincidences. Household pets started acting strangely. Zoo animals escaped. But now he can see a pattern emerging, a chilling reminder from a past that he can't--or won't--remember. As the true horror becomes clear, and terror builds upon terror, Gil can only await the coming of...the Keepers.