Ron Weasley's role in the investigation had always been the loosest one, and that looseness was precisely why Tom did not ignore him.
Harry was morally exact in a way that made him predictable once one understood the rhythm of his outrage. Hermione was intellectually exact in a way that made her dangerous but also legible through her need for sequence, evidence, and properly framed intervention. Ron was different. He did not move through the school as puzzle-solver or principled resistor. He moved through it as most children did—through appetite, loyalty, annoyance, humor, impulsive fairness, social irritation, and the strange practical elasticity that comes from not overorganizing one's own importance in every interaction.
That made him less precise.
It also made him more representative.
People spoke around Ron differently than they spoke around Harry or Hermione. They relaxed certain kinds of speech with him because he was easier to class socially. He was not likely to turn a passing remark into theory. He was not likely to respond to a petty insult by dissecting its ideological structure. He laughed easily, bristled quickly, carried emotion openly enough that others did not bother hiding theirs with the same discipline. In short, he was socially porous.
Tom had been watching that for some time.
What made Ron useful was not stupidity—Ron was not stupid, and Tom had long since discarded the laziness of underestimating him in that way. Rather, Ron acted as a medium. Remarks passed through him and came out altered not by intent but by temperature. He transmitted social material through feeling. That meant whatever reached Harry and Hermione through Ron often arrived warmer, cruder, more combustible than where it began.
Tom decided to test that explicitly.
Not directly. Direct tests on people like Ron tended to produce noise rather than information. Better to arrange an ordinary statement within his hearing and then observe its transmission.
The line itself needed to be plausible, irritating, and not especially original. Originality would only have made it memorable in the wrong way. The point was not the content. The point was the transformation.
So Tom arranged, through a second-year Slytherin already primed toward mild resentment, for a sentence to be spoken near enough to Ron that hearing it would be natural and ignoring it slightly difficult. The older boy required very little guidance beyond a nudge toward the right topic. School provided the rest.
"Gryffindors," the second-year said to his companion as they moved through a corridor just ahead of Ron, "have an easier time becoming heroes because they mistake impulse for courage and adults reward the story of it afterward."
It was not a particularly elegant insult.
That was deliberate.
The line carried enough sting to interest Ron but enough familiar social texture to avoid sounding planted. It was the kind of thing a resentful Slytherin might genuinely say after months of watching house narratives settle into predictable grooves.
Ron heard it.
Tom knew he heard it because he saw, at the edge of the corridor intersection, the tiny change in Ron's walk—the barely visible tightening through the shoulders, the fractionally faster step that meant internal protest had moved ahead of outward reaction. Ron did not confront the second-years. Also useful. Confrontation would have produced a different kind of data. Instead he carried the line away with him.
By dinner, it had become something else.
"Slytherins think Gryffindors only get praised because everyone likes the dramatic version better," Ron said.
Harry bristled at once. The response was so fast that he himself seemed to realize, a second late, that he had already accepted the line into emotional relevance before analyzing it. Hermione, more cautious, asked where Ron had heard it. Ron, already defensive because repetition itself made him feel as though he were being examined for errors, repeated the source but not the exact wording.
That mattered.
In transmission, insult became category.
What had been initially framed as a criticism of adult narrative and Gryffindor impulsivity—already unpleasant enough—arrived at Harry as a cleaner, broader social claim: that Slytherins viewed Gryffindor recognition as mere appetite for spectacle. The shift seemed small. It was not. The more abstract and generalized form made reaction easier. One can argue with an insult to a habit. One feels angrier, faster, at an insult to a whole identity.
Hermione recognized the distortion too late to stop the immediate effect. By then Harry was already angry—not wildly, not enough to lose control in some spectacular sense, but enough that the next time he saw Draco near the common corridor, loud with a small audience around him as usual, his own response came sharper than necessary.
"Got something to say directly for once?" Harry asked.
Draco, predictably, reacted with pleasure first and caution second. "Potter, if I wanted to insult Gryffindor taste I'd need more time than curfew allows."
The exchange escalated quickly from there into the sort of low, brittle verbal conflict that rarely looks dramatic from outside but does enormous interpretive work within adolescent groups. Harry gave back hard. Draco, thrilled to be operating in a mode he understood perfectly, returned twice as much. By the time a teacher intervened, the moment had not become anything formally punishable, but it had become sufficiently public to matter.
From a distance, Tom watched and learned what he needed.
Ron distorted pressure through emotion.
That made him the weak point in the trio's coordination.
Not because he was foolish.
Because he was socially porous.
Messages passed through him and came out warmer, less exact, and more combustible. Harry's moral seriousness magnified such heat once it arrived. Hermione could cool it afterward, but cooling afterward was not the same as prevention.
Useful.
Later that evening Hermione confronted Ron, though gently enough that the correction would not fracture the group. She had learned by now that truth delivered without regard to timing was one of Tom's methods, and she refused to imitate him so carelessly.
"You didn't repeat it exactly," she said.
Ron, already unhappy, scowled. "I repeated what he meant."
"No," Hermione replied. "You repeated what it felt like."
Ron opened his mouth, shut it, then opened it again with visible frustration. "Well, maybe the feeling was the point."
That answer gave her pause, because it was not entirely wrong. Tom often did use feeling as transmission medium. But in this case the distinction still mattered.
Harry, sitting opposite them with the residue of his own earlier anger now cooled into embarrassment, said quietly, "The point is that we need the exact shape, not just the sting."
Ron looked between them and saw, perhaps for the first time in clean form, how differently they heard the school. He heard living talk. They heard structure.
"Brilliant," he muttered. "So now I'm the problem."
"No," Hermione said quickly.
But they all knew, in a limited sense, that he had become one.
Not the problem.
A variable.
That was worse for Ron in some ways, because it made his role feel measurable rather than forgivable. Yet the conversation did not break him from the group. If anything, it made him more aware of the stakes in a way he had previously resisted. He disliked feeling used by Tom in even so indirect a manner, and dislike in Ron often hardened into a practical kind of loyalty once properly attached.
Tom, meanwhile, reviewed the test with satisfaction not because it had caused open conflict—that would have been too crude to be interesting—but because it had clarified structure. Ron did not simply hear rumors. He translated them. The translation obeyed emotional rather than conceptual logic. Under most school conditions, that made him ordinary. Under these conditions, where precision itself had become a weapon, it made him exploitable.
In the learning space that night, Andros noticed Tom's mood quickly.
"You have found another weakness," he said.
Tom stood with a parchment copy in hand, reviewing the day as though it were sequence rather than story. "A distortion point."
Andros frowned faintly. "You invent colder names whenever the thing itself should trouble you."
Tom ignored that. "A message passed through someone and changed form in the expected direction."
"And this pleases you."
"It clarifies the group."
Andros was quiet for a moment. "There are times when I cannot tell whether you are studying children or designing weather."
Tom set the parchment aside. "There is no useful difference if one understands pressure properly."
Andros's expression made plain what he thought of that answer.
Back in the waking world, Hermione stayed up later than usual revising the way she recorded verbal transmission. It was no longer enough, she realized, to note source and outcome. She would have to begin tracking transformation by carrier. That thought alone would have annoyed her under normal circumstances because it made the work more complicated. Now it only confirmed how far they had already been pulled into Tom's preferred terrain.
Harry lay awake too, less because of the Draco exchange itself than because of the speed with which he had reacted. He had known, intellectually, that Ron's version might not be exact. He had still answered the emotional shape of it rather than waiting. Tom would count that, he knew. Count it and store it and use it later if useful.
That knowledge did not calm him.
But it did make him decide one thing with unusual firmness before sleep finally found him.
Next time, he thought, I wait.
Across the castle, Tom came to the same conclusion about them from the opposite direction.
Not all opposition required defeating.
Some only needed to be made slightly less exact.
And slight imprecision, applied often enough, had a way of becoming its own environment.