The infusion happened on the second night.
I didn't see it directly.
None of us did that was the point of the device.
But Elena was running a shadow sense from the floor above, tracking the ambient mana shift in real time, and she sent the agreed signal at half past ten: two quiet pulses of structured mana through the building's wall channel, the equivalent of a tap on the shoulder.
I was already awake.
I'd been awake since nine-forty, sitting at my desk with the notebook open to the operational notes page, doing what I'd been telling myself all week not to do — thinking about the recording instead of leaving it alone.
The two pulses came through the wall.
I acknowledged with a single return pulse.
Then I waited.
Elena's post-session signal came at 11:08.
One pulse, extended. Done.
I went back to the blank notebook page and wrote: Session complete. Retrieve device tomorrow morning, Vane's inspection window.
