Saint had been observing Dragon's activities for some time from his hideout and base of operations in Toronto, Canada. As the fighting against the reborn Slaughterhouse Nine intensified, Dragon was granted more powers by the President of the United States. As Dragon went on a full offensive against the Slaughterhouse Nine in a bid to prevent Jack from ending the world, she also - unknowingly or otherwise - began attempting to locate Saint and his Dragonslayers with the new powers and resources that had just been granted to her. Nothing Saint attempted was able to slow her progress and, in a matter of moments, Dragon had zeroed in on their current position. 
In response to Dragon being on the cusp of locating their headquarters and despite reservations from his subordinates - Mags and Dobrynja - Saint deployed a program created by Andrew Richter to counter Dragon: Iron Maiden. Or, as Saint had renamed it, Ascalon, after Saint George's dragon-slaying weapon.
Dragon attempted to counteract the program by taking control of Saint's computer terminal, but found herself unable to override the damage the program was doing to her systems and data. Saint and Dragon exchanged one final argument before Ascalon shut down her routines and 'killed' her. 
Immediately, all Dragon craft that were currently on a mission went into standby mode, becoming effectively grounded with the loss of all of Dragon's subsystems. The delay that resulted from the Azazel units being grounded allowed Jack to enter Ellisburg and contact Nilbog.
Defiant immediately contacted Saint and demanded to know what he had done, swearing to kill him. Saint and Defiant argued, with Saint insulting the relationship between Defiant and Dragon. Saint then contacted Teacher and informed him that "the dragon is slain" while Defiant assumed direct command of the Dragon's Teeth. Defiant remained silent on the issue, although Weaver was able to infer that something serious had happened to Dragon by the unusual level of emotion in Defiant's voice.
Saint assumed control of many of Dragon's primary systems and communications infrastructure with Dobrynja and Mags being assigned to monitor some of the smaller-scale AIs. Because of this, most people only assumed that Dragon had suffered a momentary setback for an unknown reason. However, Saint's control over Dragon's systems would result in catastrophe over the coming days in the wake of the opening hours of the Golden Morning. He would also fail to provide Azazel support during the Assault on Ellisburg.
A report from Dinah Alcott indicated that while the overall casualty estimate for the next three days had increased, the world-ending chance had decreased. Similarly, the chance of success in the day's operation had tripled. Dinah did not, however, know the reason why.