A thin shaft of white light cut through the gap from the hallway upstairs.

“They have a ram,” Daniel said.

“Hold the line,” I told him. “Do not let that door swing.”

I knelt beside Marcus.

The smell of old copper and battery acid was strong.

“If I cut the blue wire, the secondary loop might trigger the detonator instantly,” Marcus said.

“What about the ground wire?” I asked.

“There isn’t one,” Marcus said. “They ran a closed loop through the chassis.”

*00:29.*

*00:28.*

My heart hammered against my ribs, but my hands remained steady.

I looked at the small metal plate inside the wiring cavity.

There was a faded serial number stamped into the zinc.

“It’s a dual-path receiver,” I said.

“Which means?” Marcus asked, his wire cutters hovering.

“It’s linked to the old security panel in the library,” I said. “The one we disconnected five years ago.”

“If the panel is disconnected, the circuit is open,” Marcus said.

“No,” I said. “We didn’t remove the backup battery in the wall.”

I remembered the day the technicians worked on the library wall.