There are two groups known as the Venatori. The original Venatori - "The Hunters" - are a group of people who fight to banish the Old Ones to Oblivion by erasing mortal awareness of them; due to the nature of their fight, they are sworn to absolute secrecy. The Venatori Umbrorum are a publicly-known group originally created by the Ventori as a cover; they are allies of the White Council and largely noncombatants.
This conflict between the Venatori and the Old Ones is known as the Oblivion War. They fight against the Old Ones, their servants, and any groups that want the Old Ones to remain as a route to power, such as the Stygian Sisterhood. They are organized into cells so no one of them knows too much information about the Old Ones. A Venator might only know as few as one other Venator. After erasing all mortal awareness of an Old One, the Old One is sealed away in Oblivion and the Venatori themselves forget about the Old One. The Oblivion War is kept a secret, and if any human finds out about it, the Venatori must kill them or recruit them. The war has been going on for the duration of mankind.
Since the war is fought over eons rather than any timescale that mortal kind can reasonably cope with, The Archive was created as the ultimate instrument of mankind in the war. Apart from making sure that the Venatori never stray from or forget their purpose, she is able to keep track of any mention of the Old Ones in writing and to listen in on certain enemy communications. Whenever she picks up a trail, she notifies a cell of Venatori agents through a blind drop and sends them to run it down. Once any and all mention of a particular Old One is gone from the world, The Archive keeps its name in memory for a safety period of a millennium or so to see if its name ever appears in writing again. Once the safety period is up, The Archive, who can then be reasonably certain the name is gone from living memory, allows herself to forget the name, thus consigning the being to oblivion.
At some point in time, the Venatori tried to banish faeries from the world. However, they were stopped by what Thomas referred to as the "G-men", Gutenberg and the Grimms.
In the seriesEdit
- Main article: Proven Guilty
In Proven Guilty, the Council's primary allies are the Venatori Umbrorum and the Fellowship of Saint Giles. The Venatori's strength is in analyzing information from a wide variety of sources. Though not capable of challenging the Red Court in face-to-face combat, they still wreak havoc on their supply chains, intelligence, and support approaching from the mortal side of it. They and the Fellowship provide the council with information on the Reds which has bought the Council needed time to regroup and to launch successful raids. 
- Main article: Backup
The original Venatori have so far appeared only in the short story Backup, in which Lara and Thomas's involvement in the Oblivion War intersects with Harry's career. In order to assist him without his knowledge, Thomas relates the history of the Venatori to Bob after extracting a promise not to tell Harry or any other mortal.
- Main article: Ghost Story