After Father Max Thompson began doing experiments to cure demons, he drew the attention of Hell who dispatched the Knight of Hell Abaddon to kill him and stop his experiments. On August 5, 1958, Abaddon ripped Father Thompson apart, but not before he told her of Josie Sands and the Men of Letters. Within the next week, Josie and Henry Winchester were sent to investigate apparent demonic possessions at a convent in Milton, Illinois. The convent was actually being used as a cover by Abaddon and her loyal demons to steal people's souls to convert them into demons. Henry and Josie exorcised two of the demons, but Abaddon proved immune and knocked Henry out. After talking with Josie, Abaddon possessed Josie to infiltrate and destroy the Men of Letters, leaving behind one demon to continue her work at the convent.
On the night of August 12, 1958, Abaddon successfully posed as Josie during her and Henry's final initiation into the Men of Letters and was granted access to the Men of Letters elders. Once inside, Abaddon attacked the elders, killing two and blinding Larry Ganem. Hearing the commotion, Henry burst into the room to witness another of the elders trying to exorcise Abaddon. However, like when Henry attempted it, the exorcism failed and Abaddon snapped the man's neck with ease. During the exorcism attempt, Larry handed Henry a box containing the Key of the Order of Letters and ordered him to keep it safe from Abaddon. Desperate, Henry fled through time using a blood sigil in order to find his son and enlist his help to protect the box. Abaddon attempted to stop him, but Henry managed to get away into the future.
Following Henry's escape, Abaddon burned down the club and slaughtered every Man of Letters she could find. Even the Grand Coven were shown to believe the Men of Letters were extinct following the event.
Of the entire order, only three were known to have survived: Larry Ganem who somehow escaped Abaddon and the fire and faked his own death though he was left blind, Cuthbert Sinclair who had been expelled from the order two years earlier and Clive Dylan who had retired after he got trapped in Oz and split into his good and dark halves.
After killing all of the Men of Letters she could find, Abaddon was able to follow Henry to the year 2013 where she chased after him for the key that Larry had given him. Though Henry was eventually killed, Abaddon was defeated and imprisoned by Henry and his grandson Dean when she proved impossible to kill. However, Abaddon would later escape and start a crusade to take over Hell in the years 2013-2014.
- Larry Ganem states that Abaddon was hired to do the massacre, calling her a "hired gun." However, Abaddon was later shown to be apparently going after the order of her own initiative once she gained Josie Sands as her vessel.