Failsafe quietly forwards your Ghost a report detailing strange disturbances in the Vex network permeating Nessus.
"A clandestine arm of Vanguard operators delivered this information for you this morning!" Failsafe says in a cheery tone.
Her tone drops as she continues, "I can't tell you who it was, but they were pretty 'Hidden', if you know what I mean? Anyway, looks like a supersecret spy mission for a supersecret Guardian."
You scan the report.
It appears as if heavy data loads are being re-formatted and imported into the Vex network from somewhere inside Nessus. Your orders are to find and stop the Vex, and secure their data for analysis.
Failsafe interrupts your reading. "Whatever is being done with that data is probably bad. Maybe investigating this will help us understand more about the Vex's goals on Nessus!"