Agent Alex Monroe is a specialist for the FBI who deals with ritualistic murders. He's brought in on a case, where he is strangely identified by name. As he and his team unravel the mystery surrounding the death of a well-known college professor and his wife in a brutal ritualistic crime, they begin to find there is more to the investigation than they ever imagined.

Prior to his death, the professor, James Burdock, was studying ancient texts that revealed another world—a world beyond our own. He spent his life studying anthropology and history, diving into the ancient cultures of the past, and it soon becomes apparent that Burdock's studies were directly related to his death. In fact, this new case connects to an old one and reveals a deeper conspiracy that has the potential to threaten the entire world.

What began as a ritualistic murder case turns out to be the first step in a process intended to open the door between hell and earth. As reality is tested and the supernatural becomes real, can Agent Alex Monroe and his team overcome the evil threatening our world? Faith, Spirituality and Science are tested as the boundaries of reality unravel. Can anyone survive the Summoning?