Mark Whitebridge, an ex-Catholic priest, is in Bydgoszcz Poland, teaching English as a Foreign Language. He meets Kasia, a journalist, and member of an amateur song and dance troupe. They start to go out with each other. In the meantime, Mark is busy helping tidy up a manuscript from an anti-cultist author, Jerzy Kowalski, who once belonged to the notorious Archers of the Apocalypse cult, more popularly known as the Insistarians, who believe that the antichrist has travelled back in time to their own age to bring forward the time of the apocalypse. Then Kowalski is murdered and so Inspector Gorski starts an investigation into the murder. Kasia and Mark also do their own investigation, to the understandable chagrin of Gorski. The murderer could be a number of people, Mark himself has a motive, he could be framing the Insistarians because his ex-wife ran away to join the cult. After a series of adventures, the truth is revealed.