While working under Cassius, Lynn honed himself into a precision bureaucratic machine.
Every piece of intelligence he provided was carefully considered again and again, held at a delicate balance.
Enough to let Cassius's squad find a genuine Tyranid node, proving Lynn's value and his "loyalty" to the Imperium.
But not enough to make the source of that intelligence seem too precise or too easily obtained, lest it arouse suspicion.
He never asked about the details of a battle, even though he thirsted for knowledge of the Sons of Medusa's tactics, equipment, and weaknesses.
Whenever Cassius or the other warriors mentioned a battle, he merely listened respectfully, showing a mixture of awe and lingering fear at the appropriate moments.
Then he deftly changed the subject, asking what "peripheral preparations" he needed to make ahead of the next mission.
He also strictly ordered his patrol team never to approach the core areas where the Space Marines had fought.
The official reasons were "preventing the spread of unknown biological contamination" and "avoiding interference with the lord angels' purification rites."
In private, he told his subordinates:
"Those places are graveyards made from the remains of Xenos demons. Who knows what radiation or poison gas is still there?
Go take a look if you want to die sooner."
The real reason was that he feared any attempt to recover battlefield biomass would leave traces he could not conceal.
He could not take that risk.
Mentally, Lynn felt as though he were walking a rusted steel wire above a bottomless abyss.
Every instruction he sent to Rena had to be rehearsed in his mind more than a dozen times, simulating every possible outcome and loophole.
His communications with Rena also grew increasingly brief, even taking on a cold, businesslike tone.
Rena did not understand what "indifference" meant anyway, which saved him the trouble of coaxing her.
Late at night, when he lay alone in the bed of his relatively spacious and luxurious new residence, nightmares became frequent visitors.
Sometimes, Cassius's dark red lenses lit up in utter darkness, locking firmly onto him like searchlights tracking prey.
Sometimes, he saw Rena's nest under saturation bombardment from Heavy Bolters and melta beams, its carapace melting through, its flesh vaporizing.
He could even "hear" the soundless shriek before Rena's consciousness perished;
More often, the two intertwined in chaotic scenes where he ran and shouted in vain.
Yet he could make no sound, only watch helplessly as everything headed toward destruction.
When he jolted awake, cold sweat soaked his sleepwear, and his heart pounded as though it would smash through his ribs.
He rose, walked to the window, and gazed at the city's perpetually flickering, sickly neon lights below.
He could not break down.
At least, not yet.
Although Lynn took twice the care, hiding his communications and operations with Rena amid the endless chaos and death of the Hive City's lower levels.
Rena, however, was an "independent node" that had broken away from the main Hive Mind.
Her very existence was the greatest variable, an anomalous current beneath calm waters that could not be fully concealed.
Cassius was more than muscle and a boltgun.
What terrified Lynn most was Cassius's brain, comparable to a supercomputer.
The Sons of Medusa's logic processors and data analysis capabilities ranked among the finest of the Astartes Chapters.
After they had efficiently wiped out four Tyranid nodes of varying sizes in succession based on Lynn's intelligence, the accompanying Tech-Priest.
A taciturn being from Mars, with over eighty percent of his body replaced by machinery, interested only in data and the mysteries of the Omnissiah.
Began a routine in-depth analysis of battlefield data.
He took the vast quantities of data gathered before and after the four battles from the Hive City's entire psychic fluctuation monitoring network, environmental pheromone sampling.
And the squad's own detector records, and fed them into the Cogitator array he carried with him.
The analysis lasted twelve standard hours.
When the final report was presented to Cassius, the sergeant's white helmet dipped slightly, the light in his dark red lenses flickering steadily.
The report contained two key findings:
First, an anomalous signal "flow."
The destroyed Tyranid nodes' biological signals, including their lingering faint psychic echoes and pheromone markers.
Had not rapidly dissipated after the main organisms perished, merging into the eternally chaotic "noise" of the Hive City's background as they normally would.
Instead, these residual signals showed a regular, slow tendency to "move."
And they were "flowing" in a common direction.
Through data modeling and source analysis, this center of attraction was traced to "an area of complex deep geological structures on the boundary between District Seven and District Eight."
That area happened to be at the heart of Inspector Lynn Corvana's jurisdiction for "anomalous organism patrols."
It was also the main area where he had previously "distinguished himself" several times.
Second, an anomalous "node."
During multiple Tyranid extermination operations, the priest discovered.
That near that particular area, some Tyranid units would "stutter" or fall out of step with the movements of the other swarms.
This subtle sense of "confusion" differed quantifiably from the highly coordinated attack patterns typical under the Hive Mind, in which units moved as readily as fingers obeyed an arm.
The Tech-Priest wrote his preliminary hypothesis in the report's notes section.
"This behavioral deviation, when compared with the model predicting 'the existence of an undiscovered anomalous Tyranid node capable of localized interference or information competition.'
Shows a match of 67.4%. This anomalous node may be located in the aforementioned area toward which the signals 'flow.'"
Cassius read the report in silence.
His chain of logic linked several points: "the efficient intelligence Lynn provided," "signal anomalies in the areas indicated by that intelligence," "abnormal behavior among Tyranid units," and "Lynn himself holding authority within the anomalous area."
A clear hypothesis formed in his cold mind.
Lynn might have some connection to that "anomalous node."
It might be cooperation, it might be control, or it might be... a deeper, more unspeakable relationship.
The mere possibility of an "anomalous independent Tyranid node" was enough to trigger the highest level of alert.
And if that node was also connected to a low-ranking Imperial official...
Cassius did not act immediately.
The patience of the Sons of Medusa was as substantial as their armor.
He needed more evidence. He needed to see a clearer picture.
He authorized the Tech-Priest to install more, better-concealed surveillance devices near the patrol team's base and Lynn's residence.
These instruments were cleverly disguised as ventilation duct maintenance modules, wall light bases, and even parts of inconspicuous roadside scrap heaps.
They subjected Lynn's daily behavioral patterns, the people coming and going, his physiological data.
And even the changes in the psychic environment around the areas he frequented, too minute for mortals to perceive, to continuous recording and analysis.
An invisible, tightly woven surveillance net quietly spread.