The call comes through his hospital's administrative office — formal FBI consultation request, standard language, nothing to flag. He accepts it through the regular channels.
The field office is on Arch Street. He has driven past it. He has never been inside. He takes the elevator to the seventh floor and the receptionist takes his name and someone comes to get him. Not Donahue — a junior agent, young, polite.
Donahue is waiting in a conference room.
The conference room is clean and functional and contains a table and six chairs and a whiteboard and, on one wall, a large pinboard. The pinboard has been covered with a pull-down screen, which is down.
"Thanks for coming," Donahue says. "Sit down."
Gideon sits.
"I want your help with something medical," Donahue says. He has his notebook. He has coffee in a paper cup from somewhere better than the office machine. "There's a toxicological question I want your read on — a specific compound interaction that keeps coming up in our investigation."
They go through it. Gideon answers. The questions are real questions, not pretextual — Donahue has clearly done his research and is asking because he genuinely wants the additional expertise. Gideon provides it. This is what makes these meetings so sustainable as cover: they are genuinely useful. Both men receive something real from them.
After twenty minutes, Donahue puts down his pen. He drinks his coffee. He looks at the screen for a moment.
"There's something I want to show you," he says. "For the medical read."
He stands. He pulls the screen up.
The board is fully visible.
It is not the whole board — not the private one in his studio apartment. This is a curated version, a selection. But it holds the timeline. It holds the methodology. It holds photographs from seven of the scenes. It holds red string. It holds a significant and specific quantity of thought.
Gideon looks at it.
He looks at it the way he looks at things that require him to be completely still — from behind the professional face, from behind the years of practice at the surface of himself. He does not flinch. He does not react.
But his breathing changes. Just once. A single, barely perceptible adjustment as he looks at the photograph from the first kill — the apartment, the kitchen, the cleaned surface near the window.
He was there. He remembers the bucket, the amber light, the city visible through the glass.
He looks at the photograph for exactly as long as he would look at any photograph in any context. Then he moves to the next one. Then the next.
"What's the medical read?" Donahue asks. He is watching Gideon's face with the absolute, patient attention of a man who has been waiting for this specific moment for four months.
"Consistent with what I said before," Gideon says. "Surgical background. Specific pharmacological knowledge. The methodology has a precision that suggests OR experience rather than theoretical training."
"Does the pattern tell you anything about motive?"
"Motive isn't my area."
"I know. But you've been looking at this from the medical angle. What does the medical angle suggest?"
Gideon looks at the board for a moment longer. He turns to Donahue.
"It suggests someone who believes they are performing a necessary function," he says. "The care taken with each method — the consistency, the cleanliness — isn't just operational. It's ethical. It's the care of someone who believes the work is justified."
Donahue holds his gaze. "Do you think they're right?"
"I think that's the question that keeps a lot of people up at night," Gideon says.
Donahue nods slowly. He stands. He pulls the screen back down.
"Thank you," he says. "That's helpful."
"Happy to assist."
"Coffee?" Donahue says. "Before you go."
"I have surgery."
"Right." He walks him to the elevator. "Same time next month?"
"My office—"
"—has the usual channels. Yes." The elevator opens. "Thank you for coming, Gideon."
It is the first time he has used his name.
Gideon steps into the elevator. The doors close.
He stands in the elevator as it descends and he looks at his reflection in the brushed steel doors and he is, to any observer, perfectly composed.
He walks out into the street. He walks two blocks. He stops and stands on the sidewalk for a moment.
Donahue pulled the screen down. Donahue let him see the board and then pulled the screen down.
Not for the medical consultation. For one specific, calculated purpose: to see what Gideon's face did.
He thinks about his breathing. The adjustment. Whether it was perceptible.
He starts walking.
He does not know. He will not know. And not knowing is the most uncomfortable thing Donahue has yet managed to do to him.