A Violent Unknown Event (or VUE) was a type of high-order chaotic effect beyond the limits of catastrophe theory. Because of this, it could affect not only those present but also others who tried visiting or learning about them. The Great Houses considered VUEs to be too unstable to utilise as weapons, though it was believed that the enemy was able to engineer them.
The Book of the War noted that information on VUEs tended to "crash, corrupt, vanish or self-falsify" by their very nature. Indeed, The Book's explanation of the enemy referenced several entries that had apparently vanished from the text, including one about Violent Unknown Events. Topics of the other vanished entries included the Churchill Index, Immaculata Formosii, the Gods of the Ainu, "Miss Hiroshima", Mohandassa, Sixth Wave Defections, and the S'tanim.
Before the War in Heaven, Thessalia tried to learn more about VUEs, going to Zo la Domini after one had occurred there. She encountered a Faction Paradox team from the Wartime future, a violation of the Protocols of Linearity made possible as a side effect of the VUE. Later, whilst attempting to relay more information to the Homeworld, she and those with her were destroyed by another event, thought to be a VUE, (PROSE: The Book of the War) which was in reality a babel attack. (PROSE: Newtons Sleep)