Trent Arian Assassination

[ShroudedSciuridae]

In the opening fiction for Field Manual: ComStar, we see Precentor Martial Trent Arian and Precentor Suzanne Mulvanery get assassinated by the Toyama sect to install Cameron St. Jamais as Precentor Martial:
 
"They both gasped as they saw the note within. Though the message it bore was only one line, its very presence spoke volumes. A fraction of a second later, the note's contents were rendered irrelevant as the car transformed into an expanding ball of flames and shrapnel."

My question for the authors is what was that one lined note?

[Chris Hartford]

It was left open to interpretation by the reader as at the time of writing many details of what were going on in the WoB were only hinted at rather than explicit, so there was meant to be some doubt as to the culprits.

Who did it I always knew though ;)