Two days after Agnes’s interview, a plain envelope arrived at Gabriel’s office.

Inside was a copy of a service receipt from the Callahan security contractor.

It listed a replacement indoor camera installed near the upstairs hallway six weeks earlier.

There was no anonymous confession or dramatic note.

Just an invoice with a serial number.

Gabriel held it under his desk lamp.

“This doesn’t prove the recording exists or what it contains,” he said.

“But it gives us a precise system to ask about.”